A Response to ‘Reply to: Superficial Pustular Folliculitis of the Face and Neck—A Non‐Infectious Eruption Responding to Topical Steroids’

Secondary Eosinophilic Pustular Folliculitis Induced by Azithromycin in an Oncology Patient.

Background: Eosinophilic pustular folliculitis (EPF), or Ofuji disease, is a rare non-infectious inflammatory dermatosis typically affecting middle-aged adults. Its clinical resemblance to infectious exanthems often leads to significant diagnostic delays, particularly in atypical age groups. Case presentation: A 15-year-old male presented with a one-month history of progressive erythematous papules, pustules, and crusted erosions distributed across the face, trunk, and extremities. The patient was initially misdiagnosed with varicella and treated with acyclovir without clinical response. Physical examination and Gram staining ruled out primary bacterial infections. Laboratory investigations revealed significant peripheral eosinophilia (12.3%). A 5-mm punch biopsy confirmed the diagnosis, showing dense eosinophilic and neutrophilic infiltration of the hair follicles and peri-adnexal structures. Management with systemic and topical corticosteroids led to rapid resolution of lesions and normalization of eosinophil levels. Conclusion: This case underscores the necessity of considering EPF in the differential diagnosis of persistent papulopustular eruptions in adolescents. Early histopathological intervention is critical to prevent unnecessary antimicrobial therapy and ensure targeted anti-inflammatory treatment.

A 14-year-old girl, under medical oncology follow-up due to a hypothalamic-chiasmatic pilomyxoid astrocytoma, was referred for evaluation of skin lesions appearing 4 days after starting trametinib. She was not taking any other medications. Physical examination showed numerous monomorphic pustules on the chest, back, and proximal arms (Figure 1). She had no general malaise, fever, or other systemic symptoms. Dermoscopy revealed pustules with perifollicular erythema, tortuous vessels and hypopigmentation of the hair shafts interspersed with pigmented hairs (Figure 2). A punch biopsy was taken from one of the follicles (Figure 3). Histopathology revealed a dermal inflammatory infiltrate with histiocytes and neutrophils surrounding the periphery of a ruptured follicle. In the stratum corneum, neutrophils, inflammatory debris, keratin remnants and clusters of spherical oval spores were identified (Figure 3, H&E, 100×). Malassezia globosa was isolated in Dixon agar. In addition to the truncal lesions, the patient also demonstrated erythema, papulopustules and yellow scales on the forehead, nose, and cheeks, involving the nasolabial folds (Figure 4). These findings were consistent with seborrheic dermatitis and folliculitis, both manifestations of Malassezia infection. Trametinib administration was discontinued and treatment was initiated with oral itraconazole 50 mg every 12 h for 2 weeks and topical miconazole 2% and hydrocortisone 1% creams, with a good response. The patient is currently stable with itraconazole 50 mg weekly and washes with ciclopirox olamine. Bacterial swabs were not performed because the clinical and histopathological findings were consistent with Malassezia folliculitis. Malassezia folliculitis is an underdiagnosed disease, often mistaken for acne [1]. In addition, patients may have seborrheic dermatitis or pityriasis versicolor at the same time. The dermoscopy of Malassezia folliculitis has been described recently [2, 3]. Findings include folliculocentric pustules, perilesional erythema, dotted/linear/tortuous vessels, grayish-brown scales [3], hypopigmentation of the hair follicle, hypopigmentation of the proximal hair shaft, coiled hairs and hair breakage. These features differ from those seen in the main differential diagnosis, acne vulgaris, which typically presents with polymorphic lesions including comedones, papules, and nodules, as well as a lack of perifollicular pigmentary or vascular changes. Other important diagnoses to consider include acute generalized exanthematous pustulosis (AGEP), which is characterized by non-follicular pustules accompanied by systemic symptoms and leukocytosis. Notably, there are no cases of AGEP associated with trametinib described in the literature, although cases have been reported with vemurafenib, a BRAF inhibitor [4]. Bacterial folliculitis does not present with perifollicular hypopigmentation, and eosinophilic pustular folliculitis, often presents with urticarial plaques and intense pruritus. Malassezia folliculitis and pityriasis versicolor share some dermoscopy features, such as folliculocentricity and follicular hypopigmentation [5]. However, the lack of pustules combined with a diffuse scaling pattern is more consistent with the second diagnosis. Wood's lamp examination can reveal green fluorescence in the affected follicles, due to metabolites produced by Malassezia spp. [6]. Similar dermatologic toxicities have been reported with other MEK inhibitors including cobimetinib and binimetinib. However, acneiform dermatitis and papulopustular rashes have been specifically related to trametinib. The most frequent histopathologic finding in trametinib-associated reactions is suppurative folliculitis, usually caused by S. aureus [7]. Recently, acneiform eruptions that resolved successfully with fluconazole have been described in a series of five patients receiving trametinib [8]. Fluconazole doses of 100–200 mg/day were administered for 2 weeks, with a maintenance regimen of one, three, or seven times per week depending on the severity. Therefore, most dermatologic toxicities, including Malassezia folliculitis, can be managed without the discontinuation of the causative drug. However, severe reactions such as AGEP-like eruptions or diffuse bacterial folliculitis, may require temporary interruption. Dermatologists should be aware of the cutaneous reactions associated with trametinib to avoid unnecessary interruption of treatment. We emphasize the use of dermoscopy in this underdiagnosed disease, as well as the effectiveness of empirical treatment with oral antifungals in follicular eruptions associated with trametinib. The authors declare no conflicts of interest.

A term male neonate presented at birth with a widespread pustular dermatosis on the face, scalp and limbs, alongside bullae and erosions on the torso. Elective caesarean delivery followed an uneventful pregnancy conceived through donor-ovum in-vitro fertilisation. He was systemically well, there was sparing of the mucosal membranes, and the hair and nails were not affected. Empirical antibiotics and aciclovir were commenced and microbial skin swabs were negative. Peripheral blood eosinophilia (2.0 × 109/L) was found; and the blood film, indirect immunofluorescence, congenital infection screen and autoiummune profile were normal. Maternal history included hypothyroidism, without any other evidence of autoimmune disease nor infection. Paternal history was unremarkable, and donor history unavailable. Differential diagnoses included immunobullous disease, neonatal lupus, eosinophilic pustular folliculitis of infancy (EPFI) and transient neonatal pustular melanosis. Cutaneous histology revealed spongiosis with subcorneal eosinophil-rich pustules and non-folliculotropic inflammation. Immunostaining showed no abnormal proliferation of any cell-type. Direct immunofluorescence was negative. EPFI was diagnosed and six weeks later the lesions had spontaneously resolved. EPFI is a rare, benign condition with a median onset at 5 months, more common in males. Aetiology is speculatively due to immune dysregulation. Only one other case presenting at birth has been reported. Scalp involvement is typical. Skin biopsy shows eosinophilic infiltrates without consistent follicular involvement. Peripheral eosinophilia is frequently seen correlating with flares. Infective causes and haematological causes including Langerhans' cell histiocytosis should be excluded. EPFI often self-remits, however generalised forms, as our case, are seldom reported. Topical corticosteroids and calcineurin inhibitors are effective.

In their recent paper, ‘Superficial Pustular Folliculitis of the Face and Neck – A Noninfectious Eruption Responding to Topical Steroids’, Huang et colleagues [1] make a significant contribution to dermatological practice by identifying and characterising a distinct, yet previously unclassified, facial pustular eruption. The authors describe a condition that, while superficially resembling well-known dermatoses like acne vulgaris, rosacea, demodicosis and Ofuji's disease among others, it possesses unique clinicopathological features that warrant its recognition as a separate entity. This differentiation is not merely an academic exercise, but has profound implications for accurate and effective patient management. The study's retrospective analysis of cases presenting with tiny, superficial and monomorphous follicular pustules on the face and/or neck provides a clear clinical profile. A key strength of the paper is its emphasis on the clinical differential diagnosis, very important if a biopsy on the face is unfeasible or refused by the patient. It is however uncommon in practice to perform a biopsy of facial papulo-pustular lesions, which likely contributes to the underrecognition of conditions like this new one. However, by providing a detailed description of the eruption's morphology, a clear diagnostic pathway, and a simple, effective treatment protocol, the authors empower clinicians to accurately identify this condition even without a biopsy. On the other hand, if a biopsy is performed, the pathologist should be familiar with this disease to avoid confounding diagnoses. Histology showed a suppurative (neutrophilic) infundibulum (peri-) folliculitis. This is not really diagnostic or specific, but helpful, because this isolated, superficial, peri-infundibular neutrophilic inflammation is somehow peculiar. In fact, both the clinical differential diagnoses of acne or rosacea may have a similar histological picture in some cases. Nevertheless, in acne, histology frequently shows comedones as well, and in rosacea one may see additionally teleangiectasia and solar elastosis in the upper dermis, demodex mite in the infundibulum, and sometimes a deeper component of mostly lymphocytic, sometimes granulomatous inflammation. Furthermore, different types of folliculitis may have different additional characteristics depending on the cause, including the presence of demodex in demodex folliculitis, the presence of hyphae or yeasts and a deep purulent inflammation in fungal folliculitis, and a more dense, deep and purulent inflammation with possible rupture of the follicle in bacterial folliculitis. Perhaps the most clinically impactful finding of the paper is the responsiveness of this condition to mid-potency topical steroids. The authors report that the pustules resolved with little to no recurrence after treatment with mid-potency topical corticosteroids (mainly betamethasone valerate). The success of topical steroids strongly reinforces the notion that the underlying pathology is inflammatory rather than infectious. This is remarkable. For years, in fact, clinicians have often resorted to prolonged courses of topical/oral antibiotics or topical antiacne agents for persistent facial pustules. Steroids are instead typically spared [2]. While the study is a retrospective case series from a single region, its findings are highly reproducible and represent a crucial step towards a more nuanced and precise approach to the diagnosis and management of facial pustular eruptions. To be noted all the patients described were adults; it would be interesting to know if children can also be affected [3]. Curiously, the study does not mention if the scalp was examined in the patients. One might wonder whether subtle or subclinical involvement of the scalp could have been overlooked. Systematic evaluation of the scalp in future cases may therefore provide further insight into the full clinical spectrum of this entity and help clarify whether its localisation is strictly limited to the face and neck or potentially more widespread [4]. Both authors contributed equally to this manuscript. The authors have nothing to report. The authors declare no conflicts of interest. Data sharing is not applicable to this article as no new data were created or analysed in this study.

This case report describes eosinophilic pustular folliculitis in a patient with long-standing, well-controlled HIV. Eosinophilic pustular folliculitis is an uncommon inflammatory skin disease often associated with low CD4 counts and immune dysregulation in uncontrolled HIV, but its occurrence in patients with well-controlled HIV has not been previously described. This case highlights the importance of considering eosinophilic pustular folliculitis as a diagnosis in individuals with well-controlled HIV who have suboptimal CD4+ T cell functional recovery. The report emphasizes that while antiretrovirals have significantly improved HIV management, unique issues related to immune dysregulation are emerging in aging patients with long-standing, well-controlled HIV.

ABSTRACT Background We have seen patients presenting with tiny, superficial follicular pustules on the face and neck that appeared distinct from common or well‐known facial pustular dermatoses, such as acne vulgaris, rosacea, demodicosis, and Ofuji's disease. Objectives We aimed to describe the clinicopathologic features, differential diagnosis, and treatment of this pustular eruption in southern Taiwan. Methods We retrospectively reviewed the medical records and clinical photos of cases presenting with tiny, superficial follicular pustules on the face and/or neck during July 2017–March 2022. Cases of rosacea, acne vulgaris, demodicosis, and Ofuji's disease were excluded. Results A total of 27 patients (26 females and 1 male; mean age of 25.2 ± 4.3 years) were included for analysis. All patients presented with monomorphous, discrete, tiny, superficial pustules on the face and/or neck. The pustules varied from a few to hundreds in number. The eruptions were distributed on the face in 12 (44.4%) patients, the face and neck in 14 (51.8%), and the neck in one (3.7%), and was itchy in 44.4%. The pustules lasted 1 day to 1 month, mostly within 1 week, before treatment, and was recurrent in 81% of cases with 2–20 episodes individually. Twenty‐four of the 25 (96%) patients responded well to steroids with complete clearance of pustules. Skin biopsy of pustules performed in three cases showed infundibular pustules filled with neutrophils and a perivascular lymphohistiocytic infiltrate in the dermis. Gram staining revealed negative finding. Bacterial cultures performed in two patients revealed Cutibacterium acnes . Conclusions Based on our observation, we would like to propose the term ‘superficial pustular folliculitis of the face and neck’ (SPFFN) for this type of eruption. It is important to be familiar with this particular type of follicular pustulosis, especially when dealing with young females as the pustules respond well to low‐potency topical steroids.

Post-zoster eosinophilic dermatitis is a rare skin disease caused by the infiltration of eosinophils into the dermis at the site of healed herpes zoster lesions. Since its initial report by Mitsuhashi and colleagues in 1997, there have been only 11 documented cases, predominantly among Asian patients. Most cases can be treated effectively with topical corticosteroids. We report a case of post-zoster eosinophilic dermatitis with a peculiar clinical manifestation and refractory course. A Japanese woman in her 40s presented with persistent pain and swelling of the right eyelid after treatment for herpes zoster in the right ophthalmic nerve. Histologically, the diffuse inflammatory infiltration of lymphocytes and eosinophils was noted in the entire dermis. Despite various treatments in addition to prednisolone, the symptoms did not improve for approximately 1 year. Eventually, systemic corticosteroid in addition to mycophenolate mofetil induced remission. This is first report of this combination for the treatment of post-zoster eosinophilic dermatitis. This case underscores the need for systemic therapy to treat refractory cases of post-zoster eosinophilic dermatitis, deviating from the more common topical corticosteroid therapy. The differential diagnosis of post-zoster eosinophilic dermatitis includes eosinophilic diseases such as eosinophilic pustular folliculitis, angiolymphoid hyperplasia with eosinophilia, and Kimura's disease, which require careful clinicopathologic investigation. This case adds to a new treatment option to our limited understanding of post-zoster eosinophilic dermatitis and its management.

Eosinophilic pustular folliculitis (EPF) is an uncommon skin condition that presents as follicular papules or pustules. The treatment of EPF is challenging because of the high relapse rates. This study aims to evaluate the efficacy and safety of tofacitinib as a treatment for EPF. We present three patients with refractory EPF who were successfully treated with tofacitinib at our clinic. We also conducted a literature review using the PubMed database to gain further insight into this promising therapy. Our patients were effectively treated with tofacitinib. To the best of our knowledge, only three other patients with EPF treated with Janus kinase inhibitors have been reported and reviewed: one treated with tofacitinib and two with abrocitinib. Complete remission was observed in all patients - both our patients and the patients in the other studies - with no adverse events or relapses reported during an average follow-up period of 4.3 months. Tofacitinib may be an emerging alternative treatment option for patients with EPF. Larger randomized controlled studies are needed to confirm these findings.

Abstract Eosinophilic pustular folliculitis (EPF) is a noninfectious follicular based inflammatory dermatosis. We present a case of a 57‐year‐old female of Indian ethnicity who developed a pustular eruption, with certain lesions displaying Koebnerization. Given that the morphologic distribution most represented the immunosuppressant EPF subtype, additional testing led to the discovery of concurrent IgA deficiency. This case highlights a particularly unusual presentation of EPF associated with IgA deficiency and Koebner phenomenon.

Eosinophilic pustular folliculitis (EPF), also known as Ofuji disease, is a rare inflammatory condition in which eosinophils infiltrate the skin, primarily around hair follicles. Several variants of the condition exist, but all exhibit sterile erythematous folliculocentric papules with or without pustules and pruritus. Common areas affected are the seborrheic areas of the body. Although the exact pathophysiology is not fully understood, the condition is seen more commonly in people of Japanese heritage, infants, and immunosuppressed patients. Immunosuppressed manifestations are divided into human immunodeficiency virus (HIV)-associated and non-HIV–associated categories. The goals of management are identification and treatment of an underlying disorder if present, relief of pruritis, and prevention of secondary infection. Here, we present the case of an adult female patient who developed EPF after a phlebectomy.

Abstract This case report documents the unique presentation of a 46-year-old woman who developed a widespread follicular pustular rash, prominently affecting her face, neck, upper chest and back, merely 4 days after receiving the Pfizer–BioNTech COVID-19 vaccine. Laboratory investigations revealed an elevated neutrophil count of 10.6 × 109 L−1 and an increased C-reactive protein level of 96 mg L−1. A skin biopsy showed a striking neutrophilic pustular folliculitis, characterized by the absence of viral inclusions and the presence of neutrophil exocytosis in the adjacent epidermis. A diagnosis of a follicular pustular variant of acute generalized exanthematous pustulosis was proposed. In response to the diagnosis, the patient was initiated on a therapeutic regimen, including prednisolone at 30 mg and topical applications of clobetasol propionate for her body and fusidic acid–betamethasone valerate for her face. The treatment approach aimed at alleviating the inflammatory response associated with the neutrophilic infiltration observed in the skin biopsy. The patient exhibited a slow yet progressive improvement in her rash, which transitioned from a pustular to a nonpustular presentation. This case contributes to the growing body of evidence regarding cutaneous manifestations following COVID-19 vaccination. The association between the patient’s symptoms and the Pfizer–BioNTech vaccine suggests a potential link, emphasizing the importance of vigilance in monitoring adverse events postvaccination. While the specific mechanisms underlying such reactions remain unclear, the prompt initiation of corticosteroid therapy, as demonstrated in this case, appears effective in managing the inflammatory cutaneous manifestations. The patient’s positive response to treatment underscores the clinical significance of recognizing and promptly addressing these rare dermatological side-effects associated with COVID-19 vaccination. In conclusion, this case report sheds light on a distinctive presentation of neutrophilic pustular folliculitis following COVID-19 vaccination, highlighting the importance of dermatological vigilance in the ongoing global vaccination efforts. Further research is warranted to elucidate the underlying pathophysiological mechanisms and establish optimal management strategies for these rare cutaneous reactions.

Abstract A 79-year-old man undergoing investigation for persistent leucocytosis and unintentional weight loss was referred with a 3-month history of an intensely pruritic rash. Examination revealed an extensive eruption of erythematous–brown papules and pustules that coalesced into confluent areas, with sparing of the inframammary region. Initial investigations included a leucocytosis of 18.2 × 109 cells L−1, with a peripheral eosinophilia of 5.8 × 109 cells L−1. Skin biopsies from his limbs exhibited parakeratosis, spongiosis, neutrophil aggregates in the stratum corneum, and upper-dermal perivascular chronic inflammation with abundant eosinophils extending into the overlying epidermis. An underlying lymphoproliferative disorder was suspected, but a bone marrow aspirate did not support this, instead exhibiting a striking increase in eosinophils with a normal spectrum of maturation. Further investigations, including liver biopsy, revealed a metastatic adenocarcinoma of colorectal origin. Telmisartan, the only recently initiated medication, was commenced 3 months prior to the onset of the rash but discontinued after 4 weeks due to pruritus. The initial working diagnosis was that of a paraneoplastic rash. The patient was initiated on topical fusidic acid/betamethasone and clobetasol, and received intravenous 5-fluorouracil chemotherapy. After 3 months, the rash remained recalcitrant. Subsequent oral prednisolone yielded partial benefit, with improvement in itch but persistent rash. Further reflection on the clinicopathological features lead to a diagnosis of papuloerythroderma of Ofuji (PEO)-like eruption with pustules. The patient was initiated on acitretin and referred for urgent phototherapy (acitretin–ultraviolet B) and is currently being observed for response. PEO is an eosinophilic dermatosis most commonly observed in male patients, and in those aged above 55 years (Desai K, Miteva M, Romanelli P et al. Papuloerythroderma of Ofuji. Clin Dermatol 2021; 39: 248–55). The pathogenesis is unknown, but associations with malignancy and drugs are documented. Features include peripheral eosinophilia and an eosinophilic infiltrate on histology (Desai et al.). A notable clinical feature is sparing of skinfolds; this feature was not initially appreciated in our patient, being relatively subtle due to his emaciated state. PEO-like eruptions with neutrophilic pustules have been previously reported (Maekawa A, Nakagawa Y, Kakuda K et al. A case of eosinophilic pustular folliculitis presenting as papuloerythroderma of Ofuji-like eruption. J Cutan Immunol Allerg 2021; 4: 37–8). This patient satisfies criteria for secondary hypereosinophilic syndrome (HES) in the context of a known underlying malignancy. The relationship between PEO and HES is not known, with only one previous report suggesting a relationship. Given the distinct clinical morphology, patient demographics, underlying malignancy, and absence of atopy, we propose that the PEO-like eruption with pustules in this case represents a clinical manifestation of paraneoplastic HES. As HES may be responsive to mepolizumab, we suggest that cases of PEO-like eruptions undergo evaluation for underlying HES, given the potential for targeted therapeutic strategies.

Abstract A 79-year-old man undergoing investigation for persistent leucocytosis and unintentional weight loss was referred with a 3-month history of an intensely pruritic rash. Examination revealed an extensive eruption of erythematous–brown papules and pustules that coalesced into confluent areas, with sparing of the inframammary region. Initial investigations included a leucocytosis of 18.2 × 109 cells L−1, with a peripheral eosinophilia of 5.8 × 109 cells L−1. Skin biopsies from his limbs exhibited parakeratosis, spongiosis, neutrophil aggregates in the stratum corneum, and upper-dermal perivascular chronic inflammation with abundant eosinophils extending into the overlying epidermis. An underlying lymphoproliferative disorder was suspected, but a bone marrow aspirate did not support this, instead exhibiting a striking increase in eosinophils with a normal spectrum of maturation. Further investigations, including liver biopsy, revealed a metastatic adenocarcinoma of colorectal origin. Telmisartan, the only recently initiated medication, was commenced 3 months prior to the onset of the rash but discontinued after 4 weeks due to pruritus. The initial working diagnosis was that of a paraneoplastic rash. The patient was initiated on topical fusidic acid/betamethasone and clobetasol, and received intravenous 5-fluorouracil chemotherapy. After 3 months, the rash remained recalcitrant. Subsequent oral prednisolone yielded partial benefit, with improvement in itch but persistent rash. Further reflection on the clinicopathological features led to a diagnosis of papuloerythroderma of Ofuji (PEO)-like eruption with pustules. The patient was initiated on acitretin and referred for urgent phototherapy (acitretin–ultraviolet B) and is currently being observed for response. PEO is an eosinophilic dermatosis most commonly observed in male patients, and in those aged above 55 years (Desai K, Miteva M, Romanelli P et al. Papuloerythroderma of Ofuji. Clin Dermatol 2021; 39: 248–55). The pathogenesis is unknown, but associations with malignancy and drugs are documented. Features include peripheral eosinophilia and an eosinophilic infiltrate on histology (Desai et al.). A notable clinical feature is sparing of skinfolds; this feature was not initially appreciated in our patient, being relatively subtle due to his emaciated state. PEO-like eruptions with neutrophilic pustules have been previously reported (Maekawa A, Nakagawa Y, Kakuda K et al. A case of eosinophilic pustular folliculitis presenting as papuloerythroderma of Ofuji-like eruption. J Cutan Immunol Allerg 2021; 4: 37–8). This patient satisfies criteria for secondary hypereosinophilic syndrome (HES) in the context of a known underlying malignancy. The relationship between PEO and HES is not known, with only one previous report suggesting a relationship. Given the distinct clinical morphology, patient demographics, underlying malignancy, and absence of atopy, we propose that the PEO-like eruption with pustules in this case represents a clinical manifestation of paraneoplastic HES. As HES may be responsive to mepolizumab, we suggest that cases of PEO-like eruptions undergo evaluation for underlying HES, given the potential for targeted therapeutic strategies.

Eosinophilic Pustular Folliculitis in an HIV-Positive 63-Year-Old Male

Sebaceous glands are not only producing lipids to contribute to the lipid barrier but are important in maintaining the homeostasis of the skin as well, which is greatly related to their immune competence. Our aim with this review is to present key studies on their possible involvement in inflammation and their crosstalk with various cell types of the immune system that altogether led to the introduction of “sebaceous-immunobiology” as a novel field in dermatology. With a focus on diseases considered to be related to sebaceous glands, such as acne, rosacea, seborrheic dermatitis, atopic dermatitis, psoriasis, lichen planopilaris, eosinophilic pustular folliculitis, and hidradenitis suppurativa, we also aim to put forward that sebaceous glands are not only innocent bystanders but active contributors in disease development.

Rarely, the gram-negative bacteria Klebsiella pneumoniae causes skin infections that are frequently challenging to identify. We present a case of an atypical presentation of this specific disease in terms of its site, lack of risk factors, and length of illness.

This is a 58-year-old woman who has had itching on her right back for 10 days; a month ago she developed blisters on her right back with no apparent cause and pain, and was diagnosed with "herpes zoster". Erythema and blisters with itching reappeared 10 days ago on the right side of the back, where the original blisters had subsided. The histopathological manifestations of the lesions were: mild hyperkeratosis of the epidermis, pustules within the stratum corneum, irregular proliferation of the spinous layer, spongiosis, local destruction of the basal layer, infiltration of eosinophils, neutrophils, histiocytes and scattered plasma cells in the dermis and subcutis. According to the medical history, clinical manifestations and histopathology of the lesions, the diagnosis was Wolf's isotopic response after herpes zoster.

To the Editor: A 47-year-old Japanese man visited our department, complaining of itchy erythema on the bilateral cheeks. Physical examination showed symmetrical infiltrative erythematous plaques with small papules and tiny pustules at the periphery, as well as papular lesions under the nostrils and around the lips (Fig. 1A). Biopsy revealed infiltration of neutrophils and eosinophils in the sebaceous glands (Fig. 1B). The patient was diagnosed as having eosinophilic pustular folliculitis (EPF), and oral intake of indomethacin (200 mg/d) resulted in a favorable effect. At the age of 56 years, he developed bronchial asthma, and a few years later, he complained of numbness of the bilateral lower legs, which was diagnosed as neuropathy. Nineteen years after the initial visit to us, he was referred to us for skin lesions. Physical examination showed brownish infiltrative plaques, papules, and vesicles on the lower extremities (Fig. 1C). Laboratory examination showed an elevated eosinophil rate in the peripheral blood (14%), and serum IgE was elevated (213 IU/mL; normal <170). Neither proteinase 3 (PR3)-anti-neutrophil cytoplasmic antibody (ANCA) nor myeloperoxidase (MPO)-ANCA was detected in the serum. HIV was negative. Histopathological examination revealed prominent infiltration of eosinophils in and around the sebaceous glands and vessels in the mid dermis (Fig. 1D). Higher magnification revealed a number of eosinophil infiltration in the vessel walls with degranulation of the infiltrated eosinophils and alteration of the affected pale-stained vessel walls, loss of endothelial cells of the affected venous vessel in the mid dermis (Fig. 1E), consistent with eosinophilic vasculitis. Neither fibrinoid degeneration of the vessel walls nor neutrophil infiltration with nuclear dust was observed. Extravascular giant cells were scattered in the dermis (Fig. 1F). Elastica van Gieson staining revealed that the affected vessels were venules. Renal disease was not observed. The patient was treated with inhaled corticosteroid for bronchial asthma, and his skin lesions were treated with topical corticosteroid ointment.FIGURE 1.: A, Facial infiltrative erythematous plaques with small papules and tiny pustules at the periphery. B, Biopsy specimen taken from the cheek showed marked infiltration of neutrophils and eosinophils in the sebaceous glands. C, Brownish infiltrative plaques, papules, and vesicles on the lower extremities. D, Histopathological features showing dermal infiltration of a number of eosinophils in and around the sebaceous glands and vessels in the mid dermis. E, Higher magnification reveals prominent infiltration of eosinophils in and around the vessel walls with eosinophilic degranulation (arrows), alteration of the affected vessel walls, and loss of endothelial cells (encircled by dotted square). F, Extravascular giant cells in the dermis. H–E, stain, original magnification: B; ×200, d; ×100, e; ×400, f; ×400).Eosinophilic pustular folliculitis is a sterile inflammatory dermatosis, frequently involving the face, presenting with annular erythematous plaques with superficial papulopustules at the periphery.1 Eosinophilic pustular folliculitis is histopathologically associated with folliculotropic infiltration of eosinophils. Our case was diagnosed as classic EPF and successfully treated with indomethacin. Thereafter, EPF did not recur, but the patient developed eosinophilic granulomatosis with polyangiitis (EGPA) 19 years later. Eosinophils play a crucial role in the pathogenesis of EGPA and release of mediators, that is, major basic protein, eosinophilic cationic protein, eosinophil peroxidase, and eosinophil-derived neurotoxin, as well as various cytokines by degranulation is important in the development of eosinophilic vasculitis.2 In EGPA, cutaneous eosinophilic vasculitis is rarely seen. The inflammatory process of eosinophilic vasculitis in EGPA begins as an angiocentric infiltrate of eosinophils in and around the small vessels.3 In the present case, angiocentric infiltrates of inflammatory cells in the affected vessels' wall were almost exclusively eosinophils without either neutrophils or histiocytes. The affected vessels were venules, and the arteries were intact. These findings suggest that the present case is the initial stage of EGPA with eosinophilic vasculitis. In addition, the present case was ANCA negative and renal involvement was absent. Previous studies have suggested that MPO-ANCA–positive patients frequently develop neutrophilic vasculitis with renal involvement, while those with eosinophil-predominant eosinophilic vasculitis frequently revealed serological ANCA negative and developed lung infiltrates, myocardiopathy, and gastrointestinal manifestations but the absence of renal involvement.4,5 Further studies are necessary to investigate the associations of cutaneous manifestations, eosinophilic vasculitis, and ANCA. Histopathological features of hypereosinophilic syndrome are eosinophilic spongiosis in the epidermis, superficial and deep dermal perivascular and interstitial infiltrate of numerous eosinophils and lymphocytes6; however, neither vasculitis nor histiocytic giant cells are observed. Therefore, hypereosinophilic syndrome was excluded in the present case. To the best of our knowledge, this is the first report of concurrent EPF and EGPA. Because EGPA occurred nearly 20 years later, the coexistence may be incidental. Nevertheless, eosinophil activation may have played a role in the induction of both disorders in our patient.