Nodular Scabies Research Articles

Diagnosis, Prevention, and Treatment of Scabies

Scabies remains a public health problem, especially in developing countries, with a worldwide incidence of approximately 300 million cases each year. Prolonged skin-to-skin contact is necessary to allow the transmission of the causative mite, Sarcoptes scabiei. Classic scabies presents with burrows, erythematous papules, and generalized pruritus. Clinical variants include nodular scabies and crusted scabies, also called Norwegian scabies. The diagnosis is based mainly on history and physical examination, but definitive diagnosis depends on direct visualization of the mites under microscopy. Alternative diagnostic methods include the burrow ink test, video-dermatoscopy, newly serologic tests like PCR/ELISA, and specific IgE directed toward major mite components. Treatment of scabies consists of either topical permethrin or oral ivermectin, although the optimal regimen is still unclear.

Mites and burrows are frequently found in nodular scabies by dermatoscopy and histopathology

Mites and burrows are frequently found in nodular scabies by dermatoscopy and histopathology

Treatment of nodular scabies with topical tacrolimus

Treatment of nodular scabies with topical tacrolimus

Scabies: A Review of Diagnosis and Management Based on Mite Biology

Scabies is a contagious parasitic dermatitis that is a significant cause of morbidity, especially outside of the United States. Scabies is diagnosed most often by correlating clinical suspicion with the identification of a burrow. Although scabies should be on the differential for any patient who presents with a pruritic dermatosis, clinicians must consider a wide range of diagnostic possibilities. This approach will help make scabies simultaneously less over- and underdiagnosed by clinicians in the community. Atypical or otherwise complex presentations may necessitate the use of more definitive diagnostic modalities, such as microscopic examination of KOH prepared skin scrapings, high-resolution digital photography, dermoscopy, or biopsy. Scabies therapy involves making the correct diagnosis, recognizing the correct clinical context to guide treatment of contacts and fomites, choosing the most effective medication, understanding how to use the agent properly, and following a rational basis for when to use and reuse that agent. Although the development of new therapeutic agents is always welcome, tried and true treatments are still effective today. Permethrin is the gold standard therapy, with malathion being an excellent topical alternative. Ivermectin is an effective oral alternative that is especially useful in crusted scabies, patients who are bed ridden, and in institutional outbreaks. Despite the availability of effective therapeutics, treatment failures still occur, mostly secondary to application error (ie, failure to treat the face and scalp or close contacts, failure to reapply medication) or failure to decontaminate fomites. Because increasing resistance to scabies treatments may be on the horizon, we propose that standard of care for scabies treatment should involve routine treatment of the scalp and face and re-treating patients at day 4 on the basis of the scabies life cycle to ensure more efficient mite eradication. Practitioners should attempt to treat all close contacts simultaneously with the source patient. To eradicate mites, all fomites should be placed in a dryer for 10 minutes on a high setting, furniture and carpets vacuumed, and nonlaunderables isolated for a minimum of 2 days, or, for those who wish to be rigorous, 3 weeks.

Nodular scabies: hypersensitivity reaction or infection?

Nodular scabies: hypersensitivity reaction or infection?

Prurigo nodularis in a woman with Stage-4 chronic kidney disease.

A 50-year-old gypsy woman presented with intense pruritus and skin lesions. She had controlled hypertension and Stage-4 chronic kidney disease with no hyperparathyroidism. No cholestatic disorder was observed. Physical examination revealed a papulonodular eruption on the limbs and the trunk and important lesions due to scratching. We consulted the dermatologist who prescribed sulpiride and a betamethasone and gentamicin cream in 10-day cycles. The lesions disappeared after 2 months of treatment. Sometimes new lesions appeared after a period of rubbing and scratching. Prurigo nodularis is a dermatosis originating from pruritus and the persistence and progression of skin lesions are strictly correlated to scratching and rubbing. The skin between the lesions is usually normal but can be xerotic or lichenified. It is more frequent in middle aged women. The clinical feature is a papulonodular eruption with a few to hundreds of lesions that range from several millimetres to 2 cm in diameter. There is a tendency for symmetrical distribution with a predilection for extensor surfaces of the limbs and the trunk. The face and the palms are seldom affected. Prominent features include crusting and excoriations with postinflammatory hyperpigmented and hypopigmented macules (Figure 1). A variety of systemic conditions have been reported to be associated with prurigo nodularis: chronic kidney disease, cholestatic disorders, Hodgkin’s lymphoma, hyperthyroidism, polycythaemia rubra vera and gluten-sensitive enteropathy. The clinical features are usually sufficient for diagnosing the disorder. The first step is to exclude any underlying disease and then to address the causes of general pruritus, which can be monitored by laboratory tests. Computerized tomography scan and chest X-rays are performed in the case of suspicion of lymphoma. Once the general causes have been excluded, the most common dermatologic differential diagnoses for prurigo nodularis are hypertrofic lichen planus, multiple keratoacanthoma and pemphigoid nodularis. If there are few lesions also nodular scabies can be considered. It is the repetitive rubbing, scratching and picking of the skin that perpetuates the disease. In the absence of any clear underlying association, prurigo nodularis is highly resistant to therapy. Potent topical glucocorticoids such as triamcinolone acetonide are often successfully employed. Topical capsaicin can be effective in the very early manifestations. Ultraviolet-based therapy is useful in diffuse and/or resistant forms of prurigo nodularis. In resistant forms, cyclosporine reduces the severity of pruritus. Thalidomide and naltrexone can also be effective in recalcitrant diffuse forms. Psychosomatic interventions can be suggested. Fig. 1. Patient’s back. Excoriations with postinflammatory hyperpigmented and hypopigmented macules.

Non-invasive diagnosis of nodular scabies: The string of pearls sign

Non-invasive diagnosis of nodular scabies: The string of pearls sign

Large CD30‐positive cells in benign, atypical lymphoid infiltrates of the skin

Cutaneous infectious and inflammatory diseases may contain a significant number of CD30-positive cells, thus mimicking lymphomatoid papulosis (LyP) or anaplastic large cell lymphoma. We reviewed our cases of non-neoplastic skin conditions with large, CD30-positive cells and searched the literature for similar cases. A total of 28 cases were included in the study: Milker's nodule (n = 8), Herpes simplex virus infection (n = 7), lymphomatoid drug reaction (n = 3), molluscum contagiosum (n = 3), nodular scabies (n = 2), leishmaniasis (n = 1), syphilis (n = 1), pernio (n = 1), ruptured infundibular cyst (n = 1) and pseudolymphoma in a scar (n = 1). CD30-positive cells were often arranged in clusters and revealed both Golgi and membrane positivity, similar to what was observed in LyP and CD30+ anaplastic large T-cell lymphoma. Analysis of our data and of those published in the literature shows that viruses and drugs are the most common cause for occurrence of large CD30-positive cells in cutaneous pseudolymphomatous infiltrates. Arrangement of these large, CD30-positive cells in small clusters is not unique to cutaneous CD30-positive lymphomas, and in many cases a precise diagnosis can be made only upon accurate clinicopathological correlation or using ancillary methods such as polymerase chain reaction analysis for viral DNA.

Histology simulating reticulosis in persistent nodular scabies.

SUMMARY Six patients with persistent nodular scabies are described. Initially the diagnosis was in doubt, and thus a lesion was biopsied in each case. The histology bore a striking resemblance to that of malignant lymphoid neoplasm in five cases. In the absence of a clinical diagnosis it was reported as such by experienced skin histopathologists. In the remaining case an accrues was seen histologically, but the type and extent of the dermal infiltrate suggested a concomitant adverse drug reaction. We feel that these histological appearances may be misleading and that even with accurate clinical details the true diagnosis may be made only on the subsequent progress of the patient.

Treatment of steroid-resistant nodular scabies with topical pimecrolimus

Treatment of steroid-resistant nodular scabies with topical pimecrolimus

Visual Diagnosis: A Family That Has an Itchy Rash

1. Tamar Stricker, MD* 2. Felix H. Sennhauser, MD* 1. 2. *University Childres’s Hospital, Zurich, Switzerland. A brother and sister are brought to the clinic for evaluation of an itchy rash of 4 months’ duration. The 4-year-old girl and 8-month-old boy each have a red, raised, and scaly rash extending over their trunk and extremities. In the previous week, they had developed inflamed, cracked bumps on their feet that intermittently bled and had a yellow discharge. Both parents also have an itchy rash. There is no history of recent illness or use of any topical agents. The family had been living in crowded conditions in Switzerland for 6 months, having emigrated from eastern Europe as refugees. Both children had received their primary immunizations for diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b, and hepatitis B upon arrival in Switzerland. The girl also had received immunization against mumps, measles, and rubella. On physical examination, the girl is afebrile and appears well. Her height and weight are normal (75th to 90th percentile and 50th to 75th percentile, respectively). Dry, abraded skin lesions with occasional thickening and crusting are present over the scalp, nape of the neck, trunk, buttocks, and extremities. The lesions are more pronounced in the axillae and flexor surfaces of the legs and have an annular configuration (Fig. 1⇓ ). Honey-colored crusts with surrounding erythema cover the lower legs and feet. Results of the remainder of the physical examination are normal. Figure 1. Annular, dry, abraded lesions on lower leg. The 8-month-old boy, also afebrile and well-appearing, has …

Cutaneous pseudolymphomas

Cutaneous Pseudolymphoma refers to a heterogenous group of benign reactive T- or B-cell lymphoproliferative processes of diverse causes that simulate cutaneous lymphomas clinically and/or histologically. The inflammatory infiltrate is bandlike, nodular, or diffuse and is composed predominantly of lymphocytes with or without other inflammatory cells. Depending on the predominant cell type in the infiltrate, cutaneous pseudolymphomas are divided into T- and B-cell pseudolymphomas. Cutaneous T-cell pseudolymphomas include idiopathic cutaneous T-cell pseudolymphoma, lymphomatoid drug reactions, lymphomatoid contact dermatitis, persistent nodular arthropod-bite reactions, nodular scabies, actinic reticuloid, and lymphomatoid papulosis. Cutaneous B-cell pseudolymphomas include idiopathic lymphocytoma cutis, borrelial lymphocytoma cutis, tattoo-induced lymphocytoma cutis, post-zoster scar lymphocytoma cutis, and some persistent nodular arthropod-bite reactions. This review attempts to discuss current aspects of the classification, pathogenesis, clinical spectrum, histopathologic and immunohistochemical diagnosis, and laboratory investigations for clonality in the various types of cutaneous pseudolymphomas. (J Am Acad Dermatol 1998;38:877-905.) Learning Objective: At the conclusion of this learning activity, participants should understand the current classification, diagnostic criteria, and modern techniques used in the differentiation of cutaneous pseudolymphomas from cutaneous lymphomas.

Leucocytoclastic vasculitis following nodular scabies

AbstractWe describe the case of an 80‐year‐old man who came to our observation with a widespread form of nodular scabies. During therapy purpuric dermatitis developed and was diagnosed as leucocytoclastic vasculitis based on histological findings. Blood chemistry revealed raised levels of circulating immunocomplexes. We report this case because of the association of an unusual form of scabies with a complication only rarely associated with this disease.

Leucocytoclastic vasculitis following nodular scabies

We describe the case of an 80-year-old man who came to our observation with a widespread form of nodular scabies. During therapy purpuric dermatitis developed and was diagnosed as leucocytoclastic vasculitis based on histological findings. Blood chemistry revealed raised levels of circulating immunocomplexes. We report this case because of the association of an unusual form of scabies with a complication only rarely associated with this disease.

Lymphocytic vasculitis: is it a specific clinicopathologic entity?

Seventy-one biopsy specimens taken at the Mayo Clinic from June 1977 through May 1981 demonstrated lymphocytic vasculitis. All specimens met the criteria for lymphocytic vasculitis, defined as (1) a predominantly lymphocytic infiltrate that involves and surrounds blood vessel walls, (2) fibrinoid necrosis of blood vessel walls, and (3) endothelial cell hyperplasia. Other histologic findings such as thrombosis, extravasation of erythrocytes, ulceration, epidermal infarction, and evidence of nuclear dust were seen only occasionally. Hypocomplementemia and other serologic abnormalities were very rare, even when lymphocytic vasculitis was extensive. The clinical diagnoses varied, with drug reaction (12 patients) and chronic urticaria (10 patients) being most frequent. In 32 cases, no specific diagnosis could be made at the time of dermatologic dismissal. In the remaining 39 cases, the diagnoses were varied and no definite clinical categories can be applied to them. We also observed typical lymphocytic vasculitis in some cases of other clinical entities, such as nodular scabies, erythema multiforme, and urticarial vasculitis, and so forth. We conclude that lymphocytic vasculitis is probably not a specific clinicopathologic entity but is more likely a reactive process, secondary to severe lymphocytic inflammation in the skin.

Immunoglobulin and complement deposits in the skin and circulating immune complexes in scabies

Sixteen patients with papulovesicular, 6 with nodular and one with a Norwegian scabies were studied. Direct immunofluorescence (IF) examination revealed C3 deposits in the skin lesions of 13 of the 18 patients. Among them were all 6 cases with nodular scabies. C3 was found mostly in dermal vessel walls and 3 of the patients also showed IgM and 2 IgA deposits at the same site. No circulating immune complexes were found, with a solid-phase C1q radioimmunoassay (RIA), but HSV- and RSV-RIA methods detected IgM antibodies of rheumatoid factor type in 5 of the 15 sera examined. These results suggest that local complement activation and perhaps also immune complex deposition may by important in the pathogenesis of the papular and nodular skin lesions of human scabies.

Pathologic Findings in Human Scabies

The histologic findings in the papular, vesicular, nodular, and Norwegian variant of scabies have in common a superficial and deep perivascular mixed inflammatory cell infiltrate of lymphocytes, histiocytes, and numerous eosinophils. A spongiotic vesicle occurs in the papulovesicular type, a dense cellular infiltrate in the nodular type, and a hyperkeratotic psoriasiform dermatitis in the Norwegian type. Eggs, larvae, and adult mites are abundant in the cornified layer of Norwegian scabies, are practically never found in biopsy specimens from lesions of nodular scabies, and are discovered only episodically in papulovesicular lesions.

Today's scabies.

In the past several years there has been a noticeable increase of scabies in the United States; the magnitude of this is not known. An expanding epidemic continues in most parts of the world. Scabies is frequently seen in many guises that may be difficult to diagnose: scabies in the clean, scabies incognito, nodular scabies, animaltransmitted scabies, scabies in infants, scabies with syphilis, and Norwegian scabies. If the diagnosis cannot be confirmed by identifying the mite, synthesis of suggestive features may establish the diagnosis. Recently adopted children from foreign countries, especially southeastern Asia, have had a high frequency of scabies, which may appear after the children arrive in the United States. Acute glomerulonephritis may develop in patients whose scabetic lesions are complicated by a virulent nephritogenic streptococcal strain. (JAMA233:882-885, 1975)

Today's Scabies

In the past several years there has been a noticeable increase of scabies in the United States; the magnitude of this is not known. An expanding epidemic continues in most parts of the world. Scabies is frequently seen in many guises that may be difficult to diagnose: scabies in the clean, scabies incognito, nodular scabies, animal-transmitted scabies, scabies in infants, scabies with syphillis, and Norwegian scabies. If the diagnosis cannot be confirmed by identifying the mite, synthesis of suggestive features may establish the diagnosis. Recently adopted children from foreign countries, especially southeastern Asia, have had a high frequency of scabies, which may appear after the children arrive in the United States. Acute glomerulonephritis may develop in patients whose scabetic lesions are complicated by a Virulent nephritogenic streptococcal strain.

Today's scabies

In the past several years there has been a noticeable increase of scabies in the United States; the magnitude of this is not known. An expanding epidemic continues in most parts of the world. Scabies is frequently seen in many guises that may be difficult to diagnose: scabies in the clean, scabies incognito, nodular scabies, animaltransmitted scabies, scabies in infants, scabies with syphilis, and Norwegian scabies. If the diagnosis cannot be confirmed by identifying the mite, synthesis of suggestive features may establish the diagnosis. Recently adopted children from foreign countries, especially southeastern Asia, have had a high frequency of scabies, which may appear after the children arrive in the United States. Acute glomerulonephritis may develop in patients whose scabetic lesions are complicated by a virulent nephritogenic streptococcal strain. (<i>JAMA</i>233:882-885, 1975)