Subcorneal pustular dermatosis associated with IgG monoclonal gammopathy of undetermined significance.

Subcorneal pustular dermatosis is a rare chronic relapsing bullous neutrophilic dermatosis. Because it can be associated with monoclonal gammopathy of undetermined significance and multiple myeloma, screening for these conditions is necessary. Herein, we present a case of subcorneal pustular dermatosis, with concurrent monoclonal gammopathy of undetermined significance, successfully treated with acitretin.

Desmoplastic intradermal spitz nevi arising within red tattoo ink.

Tattoos present a diagnostic challenge for dermatologists. Various reactions to tattoo have been identified in the literature ranging from allergic, to infectious, to neoplastic. Of the neoplastic cases identified, it is unclear whether the tattoo ink was directly causative, or if the cases were merely coincidence, as the number of cutaneous malignancies has also been on the rise. We present a novel case of two desmoplastic intradermal Spitz nevi arising within red tattoo ink.

Acantholytic squamous cell carcinoma is usually associated with hair follicles, not acantholytic actinic keratosis, and is not "high risk": Diagnosis, management, and clinical outcomes in a series of 115 cases.

BACKGROUND: Acantholytic squamous cell carcinoma (aSCC) is regarded as a high-risk variant of cutaneous squamous cell carcinoma (SCC). Acantholytic actinic keratosis (aAK) has been regarded as a precursor risk factor for aSCC. However, supporting evidence is limited. OBJECTIVE: We sought to document clinical features, histologic features, management, and outcomes in a series of aSCC cases. METHODS: Definitions of aSCC, aAK, and aSCC arising in association with aAK were applied to a consecutive series of aSCC cases. Clinical characteristics and outcomes were obtained from electronic medical records. RESULTS: Of 115 aSCC cases (103 patients, mean age 71.8 years), actinic keratosis was present in 23% (27/115) but only 7.8% (9/115) exhibited associated aAK. Ten cases (10/115, 9%) fulfilled strict histologic criteria for follicular SCC as previously defined, but 50 of 115 (43%) of our aSCC cases exhibited predominant involvement of follicular epithelium rather than epidermis. Clinical outcome (median follow-up, 36 months) was available in 106 of 115 (92%). One patient experienced regional extension (parotid), and 1 patient experienced a local recurrence (nose). No disease-related metastases or deaths were documented. LIMITATIONS: This was a single-institution retrospective study from the United States. CONCLUSIONS: The presence of acantholysis in cutaneous SCC does not specifically confer aggressive behavior, a finding that may inform clinical practice guidelines.

Mercury toxicity presenting as acrodynia and a papulovesicular eruption in a 5-year-old girl.

Acrodynia is a reaction that occurs in children who have been exposed to mercury. Mercury toxicity has systemic manifestations as well as cutaneous manifestations, which can appear similar to those found in a number of other diseases. We present a case of acrodynia caused by mercury exposure in a previously healthy 5-year-old girl who developed hypertension, palmoplantar pruritus, and a papulovesicular eruption.

Sporotrichoid granuloma annulare-like dermatitis associated with systemic B-cell lymphoma.

IMPORTANCE: Granuloma annulare is typically a benign, self-limited disease. Atypical presentations have been reported in association with systemic disease, including malignancy. Such patients may require additional diagnostic studies to assess for underlying malignancy. We report a patient with extensive sporotrichoid granuloma annulare-like dermatitis in association with systemic B-cell lymphoma. OBSERVATIONS: An 83-year-old man with a three-year history of progressive sporotrichoid annular plaques and nodules on the arm developed ipsilateral retroauricular palpable lymphadenopathy, the latter consistent with B-cell lymphoma. Multiple skin biopsies of the plaques and nodules revealed granuloma annulare-like dermatitis. Lesions were unresponsive to intralesional and intramuscular corticosteroids, antibiotics, and antifungal agents, but rapidly improved following initiation of rituximab to treat his underlying lymphoma. CONCLUSIONS AND RELEVANCE: Atypical presentations of granuloma annulare including granuloma annulare-like dermatitis warrant evaluation for systemic malignancy in a subset of patients.

Squamous cell carcinoma in the setting of chronic hidradenitis suppurativa; report of a patient and update of the literature.

Squamous cell carcinoma (SCC) developing in chronic hidradenitis suppurativa (HS) is rare, but failing to recognize the condition may have significant consequences. Dermatologists must be aware of the potential for malignant transformation and should have a low threshold for biopsy when clinical presentation is atypical. Herein we describe a 64-year-old woman with metastatic vulvar SCC that developed within an area of chronic HS. Like SCC associated with other chronic inflammatory disorders (Marjolin's ulcers), mortality is significant. Past reviews have reported death rates above 40% and our most recent update continues to support poor prognoses for these patients.

Necrolytic acral erythema masquerading as cellulitis.

Necrolytic acral erythema (NAE) is a rare cutaneous sign of hepatitis C virus infection and has recently been linked to zinc deficiency. It presents as well-demarcated erythematous plaques in a sandal-like distribution on the dorsal feet with psoriasiform epidermal hyperplasia on histology. Our patient reported a 9-month history of progressive bilateral lower extremity erythema, swelling, erosions, and nail dystrophy that failed to improve despite multiple courses of antibiotics for presumed lower extremity cellulitis. Serum studies revealed zinc deficiency. This case supports the association of NAE with both HCV infection and zinc deficiency and highlights the pitfalls in the diagnosis of chronic unrecognized NAE. Suspected cases of NAE should prompt evaluation for underlying HCV and zinc deficiency to avoid treatment delay and associated complications.

Elastin staining patterns in primary cicatricial alopecia.

BACKGROUND: Most biopsy specimens of cicatricial (scarring) alopecia can be readily subclassified as lymphocytic versus neutrophilic, but specific diagnosis remains difficult, particularly when a late stage of the disease is sampled. OBJECTIVE: We sought to document patterns of scarring highlighted by elastic tissue staining in primary cicatricial alopecia. METHODS: We documented Verhoeff elastic van Gieson staining patterns in 58 routinely embedded (vertical) biopsy specimens of cicatricial alopecia. Patterns of fibrosis included perifollicular (wedge-shaped vs broad tree trunk-shaped) and diffuse. The patterns were compared against the diagnosis obtained by independent expert clinical review, including central centrifugal cicatricial alopecia (CCCA), lichen planopilaris, traction alopecia, frontal fibrosing alopecia, discoid lupus erythematosus, and tufted folliculitis. RESULTS: Wedge-shaped perifollicular fibrosis was seen in lichen planopilaris but also in CCCA. Broad tree trunk-shaped perifollicular fibrosis was most commonly encountered in CCCA. LIMITATIONS: The retrospective nature of the study precluded temporal staging of the disease process. CONCLUSIONS: Patterns of fibrosis highlighted by elastin staining in primary cicatricial alopecia appear to be disease specific. Superficial wedge-shaped perifollicular fibrosis is associated with but may not be specific for lichen planopilaris. Broad tree trunk-like perifollicular fibrosis is specific for CCCA but not present in many cases. Elastin staining represents a useful ancillary study for the evaluation of late-stage scarring alopecia in routinely oriented punch biopsy specimens.

Assessment of the 'no eosinophils' rule: are eosinophils truly absent in pityriasis lichenoides, connective tissue disease, and graft-vs.-host disease?

Eosinophils are often present in the inflammatory infiltrate of an interface dermatitis, but the diagnostic specificity of eosinophils in interface dermatitis has not been formally evaluated. We retrospectively identified 97 examples of interface dermatitis with clinically confirmed diagnoses, including lupus erythematosus (LE), lichen planus, pityriasis lichenoides (PL), graft-vs.-host disease (GVHD), dermatomyositis (DM) and drug reaction. Diagnoses were clinically confirmed by at least two dermatologists. Slides were reviewed in a blinded fashion by at least two dermatopathologists. The average eosinophil count per 10 ×200 (×20 objective) fields was lowest for PL (0.2), DM (0.3), GVHD (0.4), and LE (0.5) [defined as Group 1] and was higher for lichen planus, drug reactions, erythema multiforme (major and minor) and viral exanthems [defined as Group 2]. Distinction between Group 1 and Group 2 was maximized using an eosinophil count cutoff of 1.1. In conclusion, eosinophils are usually rare to absent in PL, DM, most forms of LE and GVHD. While final interpretation requires a composite assessment of all features, our results suggest that the presence of even a single eosinophil within nine or ten ×20 fields argues against a diagnosis of PL, DM or LE.

Lupus erythematosus-like imiquimod reaction: a diagnostic pitfall.

Imiquimod (AldaraTM), a Toll-like receptor 7 agonist (TLR7), is known for its unique properties of being an immune response modifier and stimulator. Upon topical application, this TLR7 agonist triggers a cell-mediated immune response predominantly expressed by dendritic cells and monocytes. Local skin irritation at the application site involving erythema, pain, crusting and erosions is common and well documented. On the contrary, the specific histopathologic features associated with these treatment site reactions is not. Herein reported is a case where historical omission of imiquimod use for actinic keratosis complicated the histologic interpretation. We highlight a lupus erythematosus-like microscopic pattern and explore histopathologic features that could help in avoiding a diagnostic pitfall, as well as the relationship between TLR activation, cell-mediated immunity and skin histology.