Adjacent Normal-appearing Skin Research Articles

IL-17A/F double producing T cells, unstable Tregs and quiescent TRMs in clinically healed lesions are potential cellular candidates for recurrence of psoriasis

Biological antibodies targeting key cytokines such as IL-17 and IL-23 have revolutionized psoriasis outcome. However, the recurrence remains an urgent challenge to be addressed. Currently, most of the descriptions of skin T-cell characteristics in psoriasis are derived from lesional and non-lesional skin, and their characteristics in resolved lesions (clinically healed lesions) remain vague. In order to further elucidate the cellular mechanism of recurrence, we performed single-cell sequencing and multiplexed immunohistochemical staining of T-cell subsets in autologous resolved lesion (RL), on-site recurrent psoriatic lesion (PL), and adjacent normal-appearing skin (NS) of psoriasis. By comparing with PL and NS tissues, we identified three potential cellular candidates for recurrence in clinically healed lesions: IL-17A/F double producing T cells, unstable Tregs and quiescent TRMs. Our results provide research clues for elucidating the immunological recurrence mechanism of psoriasis, and further work is needed to deepen our findings.

The Utility of Laser Thermometry in Grading Plaque Psoriasis

Characteristics of psoriatic plaques may affect thermoregulation and the temperature of psoriatic lesions. This study assessed the utility of handheld laser thermometry in evaluating the severity of psoriatic plaques. Twenty-five patients with plaque psoriasis were examined with temperature measurements performed on psoriatic plaques, adjacent normal-appearing skin and normal-appearing contralateral skin. Scaly regions of psoriatic plaques were, on average, 1.6° F cooler than non-scaled regions. Non-scaled plaque regions were 0.5° F cooler than both adjacent and contralateral skin, on average. Sixty-six percent of plaques were cooler than contralateral skin. None of these temperature differences was statistically significant. The thickened plaque stratum corneum may have provided a less penetrable outer layer, preventing reading the true underlying temperature. We conclude that given its ease of use, handheld laser thermometry may yet be a useful plaque assessment method. Further studies are warranted.

Changes of Epidermal Thickness in Vitiligo

The stratum corneum and epidermal pigmentation have protective roles against ultraviolet radiation. Because vitiligo skin lacks melanocytes and has no potential to produce pigment, some studies suggested that the epidermis in vitiligo skin is thicker than in normal skin. However, only a few studies investigated epidermal thickness changes in vitiligo, and some of these had relatively small sample sizes. Thus, this study aimed to compare epidermal thickness between vitiligo skin and adjacent normal-appearing skin in a large cohort. Photos of hematoxylin and eosin–stained slides of vitiligo skin and adjacent normal-appearing skin were taken under a microscope. The thicknesses of the stratum corneum, viable epidermis, and full epidermis were then measured by a computerized image analyzer. A total of 206 patients (412 sections) were included. There were significant differences between vitiligo skin and adjacent normal-appearing skin in the thickness of the stratum corneum (P = 0.009), viable epidermis (P = 0.001), and total epidermis (P = 0.001). An analysis comparing skin biopsied from a sun-exposed area versus a sun-protected area showed that the stratum corneum, viable epidermis, and total epidermis were significantly thicker in vitiligo skin than in normal-appearing skin in sun-exposed areas (P < 0.05), but not in sun-protected areas. We revealed that the epidermis was thicker in vitiligo skin than in normal-appearing skin, especially on sun-exposed skin, and that this may represent a photoprotective role compensating for absent pigmentation.

In vivo confocal laser scanning microscopic features of several hypopigmented diseases

Objective To investigate the confocal laser scanning microscopic (CLSM) features of several hypopigmented diseases, including vitiligo, nevus depigmentosus, progressive macular hypomelanosis and amelanotic nevus. Methods A total of 131 patients with hypopigmented diseases were recruited in this study. CLSM was performed on depigmented lesions, adjacent normal appearing skin and lesion borders at the dermoepidermal junction level in these patients. Results CLSM showed that in progressive vitiligo, melanin was completely absent from some areas in vitiliginous skin, while some areas were present with residual dermal papillary rings which were less intact with decreased melanin content; the border of lesions was obscure; some dermal papillary rings lost integrity in normal appearing skin adjacent to the vitiliginous skin. There was a complete disappearance of pigment in vitiliginous skin, clear border of lesions and intact dermal papillary rings with bright reflected light in adjacent normal appearing skin in stable vitiligo. Dendrite-like melanocytes with bright reflected light were noted in recovery-stage vitiligo. The CLSM imaging of nevus depigmentosus and progressive macular hypomelanosis was similar: dermal papillary rings were intact with decreased melanin content and weak reflected light in depigmented lesions. No significant difference was observed in the structure of dermal papillary rings or melanin content between vitiliginous skin and adjacent normal-appearing skin of nevus anemicus. Conclusion Combined with clinical manifestations, CLSM may serve as an auxiliary tool to discriminate vitiligo, nevus depigmentosus, progressive macular hypomelanosis and amelanotic nevus.

In vivo reflectance confocal microscopy imaging of vitiligo, nevus depigmentosus and nevus anemicus

Hypopigmentary skin disorders such as vitiligo, nevus depigmentosus and nevus anemicus are common diseases in clinic. The lesions of these diseases could be similar to some extent, although each of them has its own characteristic clinical appearance and histological features. Clinically, the atypical lesions are often difficult to be differentiated. In vivo reflectance confocal microscopy (RCM) is a non-invasive, repetitive imaging tool that provides real-time images at a nearly cellular histological resolution. Our aim was to investigate the RCM features of vitiligo, nevus depigmentosus and nevus anemicus. A total of 135 patients with a clinical diagnosis of the aforementioned diseases were included in this study. The RCM images from depigmented skin, border of the white macules, adjacent normal-appearing skin and distant normal skin for all patients at the dermo-epidermal junction (DEJ) level were investigated. In the active phase of vitiligo (AVP), the RCM demonstrated a complete loss of melanin in lesional skin in eight (53; 15.1%) patients. In 45 patients (53; 84.9%) of the AVP, part of the bright dermal papillary rings normally seen at the DEJ level disappeared or part of the rings lost their integrity and the content of melanin decreased obviously. In 20 patients (53; 37.7%) of the AVP, highly refractile inflammatory cells could be seen within the papillary dermis in the lesional and adjacent normal-appearing skin, which may indicate the lesion progresses. In addition, part of the dermal papillary rings showed lack of integrity or their brightness decreased in adjacent normal-appearing skin in all the patients of the AVP. It is important to know that the RCM demonstrated an ill-defined border. In the stable phase of vitiligo (SPV), the RCM demonstrates a complete loss of melanin in lesional skin and a clear border in 31 (41; 75.6%) patients; the content of melanin and dermal papillary rings in adjacent normal-appearing skin show no changes. In 10 (41; 24.4%) patients, the dendritic and highly refractile melanocytes arose in the recovery phase of vitiligo, which may indicate the repigmentation of vitiligo. There are three kinds of repigmentation patterns under RCM: marginal, perifollicular and diffuse. Distant normal skin showed no difference from controls in both the active and the SPV. In all the patients with nevus depigmentosus, the content of melanin decreases obviously but the dermal papillary rings are intact. The dermal papillary rings show no differences between lesional skin and adjacent normal-appearing skin of nevus anemicus. Considering our results, RCM may be useful to non-invasively discriminate vitiligo, nevus depigmentosus and nevus anemicus in vivo.

Reliability assessment and validation of the Melasma Area and Severity Index (MASI) and a new modified MASI scoring method

The Melasma Area and Severity Index (MASI), the most commonly used outcome measure for melasma, has not been validated. We sought to determine the reliability and validity of the MASI. After standardized training, 6 raters independently rated 21 patients with mild to severe melasma once daily over a period of 2 days to determine intrarater and interrater reliability. Validation was performed by comparing the MASI with the melasma severity scale. The darkness component of the MASI was validated by comparing it with the difference between mexameter scores for affected versus adjacent normal-appearing skin. The area component of the MASI was validated by comparing it with the area of each section of the face determined by computer-based measurement software. The MASI score showed good reliability within and between raters and was found to be valid when compared with the melasma severity scale, mexameter scores, and area measurements. Homogeneity assessment by raters showed the least agreement and can be removed from the MASI score without any loss of reliability. Patients were limited to Hispanic, African, and Asian backgrounds. The MASI is a reliable measure of melasma severity. Area of involvement and darkness are sufficient for accurate measurement of the severity of melasma and homogeneity can be eliminated.

CUSP/p63 expression in basal cell carcinoma.

Chronic ulcerative stomatitis protein (CUSP), the most abundant cutaneous isoform of p63, is a p53-related gene essential for epithelial development. CUSP lacks the N-terminal transactivation domain found on other p53 family members and has been shown to inhibit p53 function in vitro. In this study, biopsies of normal skin (21 of 21), benign neoplasms [seborrheic keratosis (3 of 3), acrochordon (2 of 3), and verruca plana (3 of 3)], and squamous cell carcinomas (SCC) (4 of 4) displayed strong nuclear CUSP immuno-reactivity in epidermal cells. In contrast few basal cell carcinomas (BCC) (7 of 27) and sebaceous nevi (1 of 2) displayed this pattern of CUSP immunoreactivity. Thus, biopsies of cutaneous conditions characterized by sonic hedgehog (SHH) pathway dysregulation were more than 86 times as likely to lack CUSP/p63 immunofluorescence as were other cutaneous samples. Adjacent normal-appearing skin from patients with basal cell nevus syndrome (BCNS) (2 of 3) also lacked CUSP immuno-staining. Lastly, a BCC arising in a patched heterozygous mouse also lacked CUSP immuno-staining. Because CUSP mRNA and protein were detected via Northern and Western analysis in BCC samples lacking CUSP immuno-staining, we sequenced the coding region of CUSP from two non-staining BCCs but found no mutations. Therefore, CUSP appears to be present, unmutated, and yet frequently undetectable by immunofluorescence in cutaneous lesions in both humans and mice that are associated with SHH pathway dysregulation (BCCs, BCNS, and nevus sebaceous).

Confocal laser microscopic imaging of actinic keratoses in vivo: A preliminary report

Background: Real-time near-infrared confocal laser scanning microscopy (CM) offers an unprecedented method for confirming the clinical diagnosis of actinic keratosis (AK) without biopsy. Methods: Seven patients with clinically diagnosed AK underwent CM imaging over the lesion and over adjacent normal-appearing skin. Biopsy specimens were obtained from the presumed AKs in 4 patients. Results: CM detected lesional pathologic features of hyperkeratosis (71%), lower epidermal nuclear enlargement and pleomorphism (100%), and architectural disarray (57%). In contrast, cytologic atypia and architectural disarray were apparent in one patient (17%) over the adjacent, clinically normal skin. Three of 4 biopsy specimens confirmed the clinical diagnosis of AK, whereas one revealed invasive squamous cell carcinoma. Without optimizing CM for imaging hyperkeratotic skin lesions, the limited depth of penetration reached the stratum basale in only 3 lesions, precluding detection of dermal invasion in the others. Conclusion: Depth of penetration currently imposes a major limitation on CM in the diagnosis of AKs, especially in hypertrophic and hyperkeratotic lesions, which are more likely to be malignant. However, CM may become an alternative to biopsy, and its limitations may be overcome by future technologic advances in optical penetration or by simply removing the hyperkeratotic stratum corneum. (J Am Acad Dermatol 2000;43:42-8.)

Combined Acral and Flexural Reticulate Pigmentary Anomaly

<h3>To the Editor.—</h3> We describe a patient with a combination of acral and flexural hyperpigmentary features characteristic of both Kitamura acropigmentatio reticularis (KAR) and Dowling-Degos disease (DDD). The findings demonstrated in this patient support the concept that KAR and DDD are variable expressions of one genetic disorder. <h3>Report of a Case.—</h3> A 36-year-old Hispanic woman had asymptomatic acral pigmentation that had gradually progressed for 30 years. Sharply demarcated 1- to 5-mm depressed pigmented macules in a reticulate pattern were noted on the dorsal and lateral aspects of her hands, wrists, ankles, and feet. She had noted a similar, bilateral, progressive, axillary, macular hyperpigmentation for approximately 10 years (Fig 1). Her palms revealed pits and linear breaks disrupting the epidermal ridge pattern (Fig 2). Skin biopsy specimens from both the depressed pigmented skin and adjacent normal-appearing skin were obtained from the dorsal web spaces of the hand. A biopsy specimen of

Keratinocyte damage in vitiligo.

Light and electron-microscopic studies were performed on the amelanotic and adjacent normal-appearing skin in patients with vitiligo. The amelanotic skin revealed complete loss of pigment and absence of melanocytes. In addition to severe degenerative changes of melanocytes, varying degree of damage was also seen in the keratinocytes of normal-appearing skin adjacent to amelanotic skin.

Functional Evidence for Complement-activating Immune Complexes in the Skin of Patients with Bullous Pemphigoid

Previous immunofluorescent studies showing deposits of immunoglobulin and complement at the cutaneous basement membrane zone have provided evidence supporting a role for immune complexes in the pathogenesis of bullous pemphigoid. In this study the functional activity of the deposits has been examined using leukocyte attachment, a method for detecting and quantitating the biological activity of complement-activating immune complexes in tissues. When peripheral blood leukocytes suspended in serum complement were incubated with cryostat sections of lesional and adjacent normal-appearing skin from 9 patients with pemphigoid, skin from 11 normal controls and lesional skin from 14 nonpemphigoid disease controls there was significantly greater attachment of leukocytes to the basement membrane zone of lesional bullous pemphigoid skin compared to normal-appearing pemphigoid skin and skin of both control groups. A significant reduction in attachment in the absence of serum complement suggested the reaction was dependent on activation of complement by tissue-deposited complexes. Although leukocyte attachment was greater in lesional than normal-appearing pemphigoid skin, a comparison of the incidence and intensity of cutaneous IgG and complement immunofluorescence between the 2 groups showed no significant differences. Furthermore, no correlation between leukocyte attachment and serum titers of immunoglobulin G or complement-binding anti-basement membrane zone antibodies was observed. These results suggest that immune reactants in lesional pemphigoid skin are functional complement-activating immune complexes, that differences exist between the activity of complexes in lesional and normal-appearing pemphigoid skin and may explain why lesions develop at some sites and not others.