Dermatology Online Journal

Statistical mistakes can undermine research credibility. Identifying common errors may help researchers avoid them in future studies. This study evaluated the frequency and types of statistical mistakes in dermatology journal articles and identified article characteristics that predict these errors. A cross-sectional analysis was conducted on articles published in the 2023 volumes of 8 dermatology journals. Articles were screened for statistical tests, with a target sample of 200 selected pseudorandomly. Multivariable logistic regressions assessed predictors of statistical mistakes, including journal impact factor, statistician involvement, funding source, first author highest degree, and statistical package. Of the 189 articles analyzed, 78% contained at least one statistical mistake. Reporting mistakes were found in 67% and test selection errors in 46%. The absence of statistician involvement (aOR 2.49, P=0.03) and low journal impact factor (aOR 3.82, P=0.02) predicted the presence of at least one mistake. This sample from 8 journals is not representative of all dermatology literature. Original data were not available for testing of test assumptions, so appropriate test selection was determined using statistical conventions. Statistical mistakes are prevalent in dermatology literature. Researchers should review statistical best practices and consider involving a statistician in their work.

Malignant melanoma lesions arising in tattoo pigment pose diagnostic challenges, but current literature lacks quantitative data on delayed diagnosis. This study reports a new case involving multiple melanoma lesions in tattoo pigment, alongside a systematic review of past cases. Our objectives were to evaluate the potential for delayed diagnosis in patients with melanoma lesions in tattoo pigment and its impact on prognosis, comparing tumor characteristics with large-scale melanoma studies. A systematic review was conducted using PubMed and Ovid MEDLINE. Included studies were English-language reports of melanoma lesions in tattoo pigment, identifying new cases via case reports/series. Independent review and discussion resolved discrepancies. The review yielded 37 articles with 42 reports of melanoma lesions in tattoo pigment, totaling 43 cases. Of these, 35 were invasive, with mean and median Breslow thickness of 2.49mm and 0.9mm, respectively, which is higher than in large-scale studies. Patients also had a higher incidence of invasive lesions at diagnosis. The increased Breslow depth and risk of dermal invasion suggest a higher risk for delayed diagnosis and worse prognosis in melanoma arising in tattoo pigment. Further analysis of dermatoscopic differences is needed to improve diagnostic guidelines and avoid delayed diagnosis.

Dermatofibrosarcoma protuberans is an uncommon locally aggressive mesenchymal neoplasm that classically presents with a proliferation of monomorphic spindled cells with thin nuclei and scant cytoplasm. We report a man in his twenties who presented for an unrelated skin concern and was incidentally noted to have a large, atrophic scar-like depression of the left supraclavicular neck and shoulder. The plaque was photographed and the patient was instructed to follow-up in one year, and careful photo comparison revealed the lesion had subtly enlarged and darkened in color. Accordingly, a punch biopsy revealed features of myxoid dermatofibrosarcoma protuberans, a dermal proliferation of spindled cells with mucinous degeneration and more cellular areas with extensive nuclear palisading resembling the Verocay bodies of a neurofibroma. Clinicians should be aware of the broad clinicopathologic spectrum of DFSP to ensure timely diagnosis and effective treatment. Myxoid dermatofibrosarcoma protuberans is a rare and clinically challenging diagnosis, as the mucinous areas can impart a bluish hue. Dermatofibrosarcoma protuberans can also be atrophic, with the loss of the normal dermal thickness corresponding to a clinical appearance easily mistaken for anetoderma or atrophic scar. Palisaded nuclei resembling the Verocay bodies of schwannoma are sometimes seen and can further obfuscate the diagnosis.

Mature plasmacytoid dendritic cell proliferation is a condition associated with myeloid neoplasms, most commonly chronic myelomonocytic leukemia. Plasmacytoid dendritic cells can resemble lymphocytes and histiocytes morphologically and immunophenotypically. Mature plasmacytoid dendritic cell proliferation may therefore go unrecognized if the diagnosis is not suspected and appropriate stains for plasmacytoid dendritic cells are not performed. Herein, we present a case of mature plasmacytoid dendritic cell proliferation masquerading clinically and histologically as histiocytoid Sweet syndrome. The patient, who had previously been diagnosed with mature plasmacytoid dendritic cell proliferation that presented as pink, edematous, pruritic papules and plaques, had initially resolved following induction chemotherapy for acute myelomonocytic leukemia. However, he presented later with indurated purpuric plaques on the trunk within weeks of receiving filgrastim for neutropenia. Biopsies demonstrated marked dermal edema, interstitial, superficial, and deep infiltrate with histiocytoid appearing cells concerning for histiocytoid Sweet syndrome. Further work-up demonstrated that the infiltrate was predominantly composed of CD3-, CD4+, CD34-, CD123+, CD56-, CD68-, myeloperoxidase negative mononuclear cells consistent with mature plasmacytoid dendritic cell proliferation. This case demonstrates that MPDCP should be considered in the differential diagnosis of eruptions that clinically and histologically look like histiocytoid Sweet syndrome but stain negatively for myeloperoxidase.

Axillary web syndrome, or cording, presents as fibrotic bands that develop beneath the skin, causing pain and restricted shoulder movement. Axillary web syndrome typically arises as a complication following axillary surgery for breast cancer. We present a unique case of a 38-year-old woman with no history of malignancy, breast surgery, or trauma, who developed AWS following a punch biopsy after initially presenting with a subcutaneous nodule in the right axilla. This case highlights the need for increased exploration of the pathogenesis of axillary web syndrome, suggesting a potentially higher incidence of axillary web syndrome than currently reported owing to its self-limiting nature. In addition, the case demonstrates the importance of dermatological awareness of this condition, as its presentation is not limited to breast cancer patients who have undergone major axillary and breast procedures.

Gender-affirming hormone therapy with testosterone may be a component in the treatment plan for transmasculine individuals. Secondary erythrocytosis induced by testosterone therapy and its subsequent complications, such as pruritus, have been reported in the literature in cisgender men. This report presents two transmasculine patients who developed generalized pruritus shortly after initiating testosterone therapy for gender-affirming care. Both patients exhibited elevated hemoglobin and hematocrit levels indicative of testosterone-induced erythrocytosis. Despite treatments, including topical corticosteroids, antihistamines, gabapentin, and benzodiazepines, their symptoms persisted. Symptomatic relief was achieved through therapeutic phlebotomy. The occurrence of polycythemia vera-like pruritus underscores a significant but less commonly recognized side effect of testosterone therapy. Balancing effective gender-affirming care and patient goals with the management of associated side effects is essential for optimizing patient outcomes.

We present a case of human papillomavirus-associated squamous cell carcinoma arising between the ventral toes. A 60-year-old man presented with a 6-year history of a growth between the right fourth and fifth toes that had previously been thought to be secondary to hammertoe deformity. Initial biopsy favored verruca vulgaris with associated fungal hyphae and he was treated accordingly. Subsequent biopsy showed squamous cell carcinoma in situ with positive for high-risk human papillomavirus subtypes 16 and 18. He was successfully treated with Mohs surgery. This is the first published case of human papillomavirus 18-associated interdigital squamous cell carcinoma of the toes treated with Mohs surgery.

Discoid lupus erythematosus can present in various atypical forms, posing significant diagnostic challenges as it can mimic other infectious or neoplastic dermatoses. Herein, we detail two cases of strictly unilateral, multifocal discoid lupus erythematosus and compare them with previously reported cases. This report contributes to the limited literature on this unusual presentation, particularly in individuals with skin of color.

An 82-year-old man with a history of hypertension, thyroid nodule, and parkinsonism on carbidopa/levodopa was referred for a sudden eruption of scattered purpuric macules. He noted fatigue, weakness, ankle swelling, abdominal fullness, headaches, lapses in memory, and dysphasia. On physical examination, he had thin and atrophied upper extremities and central obesity, as well as nonblanching red to purple macules on the lower abdomen and ecchymosis on bilateral arms. The patient denied the use of any corticosteroids. Lab workup showed an abnormally high post-dexamethasone cortisol level, which raised suspicion for Cushing syndrome. Further inquiry into the patient's medication and supplement history revealed that he was consuming Artri King, a supplement marketed for the treatment of joint pain and arthritis. Artri King can lead to numerous dermatological manifestations akin to endogenous Cushing syndrome such as thin skin, easy bruising, and purple striae. This case illustrates the potential risks of over-the-counter dietary supplements, which often circumvent the strict Food and Drug Administration regulations applied to prescription medications, posing significant health hazards to users. There is critical need for transparency and regulation of supplements.

Inflammatory linear verrucous epidermal nevus is a rare benign epidermal nevus that classically presents in childhood with pruritic, linear, erythematous, scaly coalescing papules and plaques distributed along the lines of Blaschko. We report a 28-year-old woman with a long-standing history of photosensitive pruritic dermatosis, exhibiting minimal improvement with topical therapies, including clobetasol, cholesterol/lovastatin cream, and ruxolitinib. Histologic evaluation revealed psoriasiform epidermal hyperplasia with focal cornoid lamella. The combination of clinical and histologic features led to the diagnosis of porokeratotic inflammatory linear verrucous epidermal nevus, a proposed variant of inflammatory linear verrucous epidermal nevus with overlapping features of linear porokeratosis. The patient demonstrated substantial improvement following CO2 laser therapy, highlighting its potential as an effective treatment option for this variant of inflammatory linear verrucous epidermal nevus.

Colloid milium is a rare and clinically underdiagnosed dermatosis, characterized by deposition of amorphous material in the dermis. Definitive diagnosis is established by histopathology which reveals the presence of colloid in dermal papillae. Photo-exposed areas are the most frequently involved sites and include dorsa of hands, neck, and ears. We present an adult man with an outdoor occupation who had longstanding chronic actinic dermatitis. For one and a half years he had been developing skin colored to slightly erythematous papules and nodules on his face, anterior neck, and dorsal aspect of the hands, symmetrically. These discrete lesions arose on the background of his eczematous sun exposed skin. Skin biopsy for histopathology of these papules showed deposition of amorphous colloid material in the dermal papillae with an uninvolved Grenz zone along with dermal solar elastoses. The coexistence of colloid milium with chronic actinic dermatitis in the same patient has not been previously reported in the medical literature even though both conditions are precipitated by chronic sun exposure. Similarly, such extensive lesions of colloid milium have rarely been reported and we ascribe this to his profession, compelling him to spend numerous hours in the sun every day.

Purpura fulminans is a rare life-threatening presentation of disseminated intravascular congestion that presents with widespread purpura and skin necrosis secondary to considerable tissue thrombosis. It usually occurs in pediatric patients and can have various causes with acute infection being the most common. Common infectious triggers include Neisseria and Streptococcus pneumoniae as well as varicella. Our report describes a generally healthy adult patient who developed purpura fulminans in the setting of Group A Streptococcus bacteremia. Group A Streptococcus is a rare cause of purpura fulminans in adult patients with only a few documented cases reported in the literature.

Osteoma cutis miliaris is a rare condition of bone formation in the dermis, often misdiagnosed. We present a 52-year-old woman with asymptomatic, hard papules on the forehead, initially treated as acne. Biopsy confirmed osteoma cutis, and surgical removal via microincisions successfully extracted the lesions with no recurrence. This case emphasizes the importance of accurate diagnosis and highlights a minimally invasive approach as an effective, low-risk treatment option.

Enfortumab vedotin is a first-in-class antibody-drug conjugate used in the treatment of locally advanced or metastatic urothelial carcinoma. A range of cutaneous adverse events has been reported with enfortumab vedotin use. Nectin-4, a transmembrane protein overexpressed by urothelial carcinoma cells, is the intended target of enfortumab vedotin. However, as nectin-4 is also expressed by epidermal keratinocytes, sweat glands, and hair follicles, it is believed that cutaneous toxicity is mediated though off-target delivery of enfortumab vedotin. We present a patient with metastatic urothelial carcinoma who developed a grade 3 bullous dermatitis after his second treatment cycle of enfortumab vedotin and pembrolizumab therapy. Histopathologic findings showed intraepidermal blisters with prominent dyskeratotic and necrotic keratinocytes. Temporary withholding of enfortumab vedotin and pembrolizumab and treatment with potent topical corticosteroids led to significant improvement and enfortumab vedotin (with pembrolizumab) was resumed at a reduced dosage of enfortumab vedotin without recurrence. We present this case to highlight the clinical manifestations, histopathologic findings, and management of enfortumab vedotin-induced cutaneous toxicity.

A 39-year-old man with an unrecognized facial sinus tract under his chin initially presented with an innocuous lesion resembling an acne pimple. The patient's journey began with dermatologic intervention, involving systemic and topical antibiotics. Upon treatment failure, referral to a general dentist revealed a carious lesion on the lower right lateral incisor, prompting further investigation. A subsequent referral to an endodontic specialist led to the diagnosis of a chronic periapical abscess, and an endodontic intervention was initiated. Despite the persistence of intracanal purulent exudate, a strategic application of pure calcium hydroxide was implemented, followed by a temporary seal. A two-year follow-up demonstrated complete healing of the periapical lesion and resolution of the extraoral cutaneous sinus tract. The report showcases the intricate diagnostic journey, meticulous endodontic intervention, and successful management of an extraoral cutaneous sinus tract mimicking scar or cyst, emphasizing the importance of a correct diagnosis to avoid ineffective treatment.

Cutaneous collagenous vasculopathy is a rare microangiopathy that presents with asymptomatic telangiectasias and distinct histopathological features, including hyaline material deposition in vessel walls. Diagnosis requires biopsy and differentiation from other telangiectatic disorders. Current treatment options are limited, but increased awareness may improve recognition and management of this rare condition. Herein, we describe an unusual presentation of cutaneous collagenous vasculopathy as asymptomatic, pink, mat-like telangiectatic macules on the trunk and proximal extremities of a 62-year-old woman. Histopathologic evaluation revealed dilated superficial dermal vessels with hyaline thickening of the vessel walls, consistent with a diagnosis of cutaneous collagenous vasculopathy.