General dermatology and dermatology in primary healthcare

This article features a 54-year-old woman with a chronic growth on her left buttock. This patient’s case posed a diagnostic challenge based on the presence of multiple soft nodules and the histological findings of mature adipocytes within the dermis.

Leukemia Cutis in Relapsed Acute Myeloid Leukemia: A Call for Distinct Classification

BACKGROUND Acute myeloid leukemia is characterized by dysregulated proliferation and maturation arrest of myeloid precursors, precipitating a spectrum of complications. Among these, leukemia cutis refers specifically to ectopic deposition and proliferation of malignant myeloid cells within the skin. This infiltration pathogenesis remains unclear. Although there are numerous reports of leukemia cutis in the setting of acute myeloid leukemia or primary acute myeloid leukemia, there are no specific reports of leukemia cutis in the setting of relapsed acute myeloid leukemia. CASE REPORT A 59-year-old woman, with a history of remission from poor-risk acute myeloid leukemia, previously treated with chemotherapy and allogenic bone marrow transplant, presented with shortness of breath, lethargy, anemia, thrombocytopenia, and subcutaneous nodules on lower extremities. Leukemia cutis was diagnosed, in the setting of relapsed acute myeloid leukemia. After unsuccessful salvage chemotherapy and being deemed unsuitable for further treatment, she pursued palliative care and died a month later. CONCLUSIONS Our case highlights a lack of reporting or making a distinction of those patients with relapsed acute myeloid leukemia and leukemia cutis. Consequently, it can be deduced that patients who simultaneously have relapsed acute myeloid leukemia and leukemia cutis are expected to fare worse in terms of clinical outcomes than those with primary acute myeloid leukemia and leukemia cutis. Relapsed acute myeloid leukemia patients with leukemia cutis should be classified as a distinct group, warranting further research into aggressive therapeutic targets and survival rates, while emphasizing the need for more vigilant follow-up and lower biopsy thresholds for cutaneous lesions in patients with treated hematologic malignancies.

Black Fungus of the Foot: An Unusual Presentation of COVID-19-Associated Mucormycosis

Mucormycosis, also known as black fungus, is a rare but aggressive fungal disease with high morbidity and mortality rates that tends to affect patients who are severely immunocompromised. Early recognition of the infection and prompt intervention is critical for treatment success. In recent years the coronavirus disease of 2019 (COVID-19) pandemic has resulted in a surge in the number of cases of mucormycosis. This study aims to report an unfortunate event involving an immunocompromised elderly man with mucormycosis of the foot who died as a result of sepsis caused by COVID-19. It is important to have a high clinical suspicion for mucormycosis when a clinical lesion develops, and to appropriately perform biopsy the lesion in question, particularly in the context of COVID-19. Raising awareness of COVID-19-associated mucormycosis may allow for early detection of the disease, thus enabling the initiation of rapid treatment, ultimately saving lives.

Spatial transcriptomics stratifies psoriatic disease severity by emergent cellular ecosystems

Whereas the cellular and molecular features of human inflammatory skin diseases are well characterized, their tissue context and systemic impact remain poorly understood. We thus profiled human psoriasis (PsO) as a prototypic immune-mediated condition with a high predilection for extracutaneous involvement. Spatial transcriptomics (ST) analyses of 25 healthy, active lesion, and clinically uninvolved skin biopsies and integration with public single-cell transcriptomics data revealed marked differences in immune microniches between healthy and inflamed skin. Tissue-scale cartography further identified core disease features across all active lesions, including the emergence of an inflamed suprabasal epidermal state and the presence of B lymphocytes in lesional skin. Both lesional and distal nonlesional samples were stratified by skin disease severity and not by the presence of systemic disease. This segregation was driven by macrophage-, fibroblast-, and lymphatic-enriched spatial regions with gene signatures associated with metabolic dysfunction. Together, these findings suggest that mild and severe forms of PsO have distinct molecular features and that severe PsO may profoundly alter the cellular and metabolic composition of distal unaffected skin sites. In addition, our study provides a valuable resource for the research community to study spatial gene organization of healthy and inflamed human skin.

Bictegravir-Induced Drug Reaction With Eosinophilia and Systemic Symptoms in a Patient With Acute Human Immunodeficiency Virus

Although drug reaction with eosinophilia and systemic symptoms (DRESS) is associated with antiretrovirals, there are no published reports of bictegravir-induced DRESS. Bictegravir is recommended as first-line treatment for patients with human immunodeficiency virus (HIV). Recognition of DRESS, its skin manifestations, and potential complications is vital for appropriate care and management of acute HIV.

Clinical and histopathological spectrum of delayed adverse cutaneous reactions following COVID-19 vaccination

Background

As more people become vaccinated against the SARS‐CoV‐2 virus, reports of delayed cutaneous hypersensitivity reactions are beginning to emerge.

Methods

In this IRB‐approved retrospective case series, biopsy specimens of potential cutaneous adverse reactions from the Pfizer‐BioNTech or Moderna mRNA vaccine were identified and reviewed. Clinical information was obtained through the requisition form, referring clinician, or medical chart review.

Results

Twelve cases were included. Histopathological features from two injection‐site reactions showed a mixed‐cell infiltrate with eosinophils and a spongiotic dermatitis with eosinophils. Three biopsy specimens came from generalized eruptions that showed interface changes consistent with an exanthematous drug reaction. Three biopsy specimens revealed a predominantly spongiotic pattern, consistent with eczematous dermatitis. Small‐vessel vascular injury was seen in two specimens, which were diagnosed as urticarial vasculitis and leukocytoclastic vasculitis, respectively. There were two cases of new‐onset bullous pemphigoid supported by histopathological examination and direct immunofluorescence studies. Eosinophils were seen in 10 cases.

Conclusions

Dermatopathologists should be aware of potential cutaneous adverse reactions to mRNA‐based COVID‐19 vaccines. Histopathological patterns include mixed‐cell infiltrates, epidermal spongiosis, and interface changes. Eosinophils are a common finding but are not always present. Direct immunofluorescence studies may be helpful for immune‐mediated cutaneous presentations such as vasculitis or bullous pemphigoid.

Histopathologic reaction patterns to differentially cross-linked hyaluronic acid fillers: A retrospective case series

BACKGROUND

Hyaluronic acid filler reactions have been increasingly observed in recent years. Our study investigates whether the increased number of filler reactions observed since 2014 is associated with a specific histopathologic inflammatory pattern and type of filler.

METHODS

The institution's dermatopathology electronic database was retrospectively searched for histopathologic reactions to hyaluronic acid from January 2014 to December 2019. The age, sex, type of filler, procedure, location, and histopathologic patterns were recorded.

RESULTS

From 2014 to 2019, there were 15 cases of granulomatous reactions to hyaluronic acid filler. In 10 of these cases, there was a characteristic inflammatory pattern characterized by tightly cuffed palisades of histiocytes with varying numbers of eosinophils. Of the 11 cases in which the type of filler was known, all used Vycross technology, a novel manufacturing process in the production of hyaluronic acid filler.

CONCLUSION

A characteristic histopathologic pattern of discrete foci of tightly cuffed palisaded granulomas with eosinophils is associated with fillers manufactured using Vycross technology.

The "bumpy" adolescent nose: Acne associated angiofibroma-like nasal papules

BACKGROUND/OBJECTIVE

Papular scars are a recently described clinical phenotype of acne scarring characterized by papules occurring on the nose and chin. We have observed a similar presentation of nasal papules among patients seen in our clinic for acne and sought to further characterize the clinical and histopathological characteristics of this entity.

METHODS

In this single-site case series, a retrospective review of electronic medical records of patients with nasal papules in association with acne vulgaris between April 2018 and April 2019 was performed. Clinical and histopathologic findings were recorded.

RESULTS

We identified 20 patients who presented with a similar clinical phenotype of predominantly skin-colored, dome-shaped papules concentrated on the nose and chin in association with a history of more classic facial acne vulgaris. Papular lesions were seen predominately in adolescent Hispanic males. Concomitant acne on other areas of the face was identified in 18 patients at presentation while two patients had a history of adolescent acne. Biopsies were performed for five patients. Histopathologic examination demonstrated features of fibrosis and dilated thin-walled blood vessels, typical of angiofibromas.

CONCLUSION

We present a series of adolescent patients with large, flesh-colored to erythematous papules seen predominantly on the nose. These lesions are histologically indistinguishable from angiofibromas and may represent an under-recognized yet disfiguring sequela of acne that may disproportionately affect adolescents with skin of color.

Neutrophilic panniculitis arising from hematogenous spread of methicillin-resistant Staphylococcus aureus

Infectious panniculitis from hematogenous spread is uncommon and usually occurs in immunocompromised patients. Dissemination of gram-positive organisms to the subcutaneous tissue is rare with only several reports of disseminated panniculitis caused by Streptococcal species. We report a case of an immunocompetent 2-year-old boy presenting with diffuse neutrophilic panniculitis arising from methicillin-resistant Staphylococcus aureus septicemia. This case represents a highly atypical manifestation of severe MRSA infection and serves as a reminder to consider MRSA as a cause of disseminated neutrophilic panniculitis, particularly in high-risk populations.

A case of porphyria cutanea tarda in the setting of hepatitis C infection and tobacco usage

Porphyria cutanea tarda (PCT) is the most common type of porphyria, presenting in middle-aged patients with a photodistributed vesiculobullous eruption, milia, and scars. Porphyria cutanea tarda occurs in relation to inhibition of uroporphyrinogen decarboxylase, a key enzyme in the heme biosynthesis pathway. A number of genetic and acquired factors increase susceptibility to PCT by reducing uroporphyrinogen decarboxylase activity. A handful of other vesiculobullous conditions may mimic PCT both clinically and histologically; therefore, both skin biopsy and laboratory evaluation are helpful in confirming the diagnosis. We report a case of PCT in the setting of cigarette usage and untreated hepatitis C infection.

Learning Analytics to Enhance Dermatopathology Education Among Dermatology Residents

BACKGROUND: With the advent of digital microscopy, learning analytics can be leveraged to advance teaching of dermatopathology in dermatology residency. OBJECTIVE: To analyze the acquisition and decay of dermatopathology visual recognition skills and areas of diagnostic confusion amongst residents using learning metrics generated by a web-based learning tool. METHODS: This was a prospective, longitudinal study of dermatology residents who studied digital photomicrographs of 18 routine diagnostic entities using an online software platform. Residents at different years of training were given 60 minutes to complete assessments on three occasions (initial test with follow-ups at one and three months). RESULTS: 4,938 responses were analyzed. Accuracy and time to diagnosis improved within each assessment and between the first and second assessments. First year residents showed knowledge decay when tested at three months (67% vs 64%; P=0.002) while third year residents retained knowledge and continued to improve upon their accuracy after three months (83% to 91%, <0.001). Learning analytics highlighted diagnostically challenging cases for residents that contradicted experts’ predictions (R=0.48). CONCLUSIONS: The use of learning analytics and interactive digital platforms enhances dermatopathology curriculum development by identifying challenging diagnostic entities, assessing mastery of subject material, and optimizing review schedules. J Drugs Dermatol. 2019;18(12):1231-1236.

Photolichenoid dermatitis: a presenting sign of human immunodeficiency virus

Photolichenoid dermatitis is an uncommon eruptive dermatitis that often occurs in association with a photosensitizing drug. Photodermatitis, in general, is an uncommon clinical manifestation of human immunodeficiency virus (HIV), most often affecting patients of African and Native American descent. Photolichenoid dermatitis has infrequently been reported in patients with HIV who have not been exposed to a photosensitizing drug. We report a case of an African patient with a photodistributed depigmenting eruption without exposure to a photosensitizing drug. Histologic examination revealed a patchy perivascular and bandlike lymphocytic infiltrate with melanophages, interface changes, and dyskeratotic keratinocytes, consistent with photolichenoid dermatitis. Laboratory examination was significant for a positive HIV-2 antibody. Photolichenoid dermatitis may be a presenting sign of HIV infection and may not necessarily be associated with exposure to a photosensitizing drug. Testing for HIV should be done in patients who present with photodistributed depigmenting eruptions, even in the absence of exposure to a photosensitizing drug, and particularly in patients of African and Native American descent.