Dermatology Online Journal

Cantharidin, a natural toxin produced by the blister beetle, is a topical agent that induces acantholysis of the epidermis, breaking down desmosome plaques through the release of serine proteases. Cantharidin is available in three liquid forms: Ycanth (0.7%), Canthacur (0.7%), and Canthacur PS (1% cantharidin, 30% salicylic acid, 2% podophyllotoxin). Ycanth is used to treat molluscum contagiosum (MC). Canthacur is routinely used to treat a variety of dermatologic conditions including MC, plantar warts, and common warts, whereas Canthacur PS is a more potent formulation indicated for treatment of plantar warts only. The objective of this review is to highlight the efficacy, safety, and diverse use of topical cantharidin in the treatment of various skin conditions. Conditions in which treatment with topical cantharidin yielded a good-to-excellent response include MC, plantar warts, and common warts. Topical cantharidin treatment of anogenital warts yielded mixed results. None of the indications reviewed herein yielded a poor response to topical cantharidin. Overall, topical cantharidin resulted in a good-to-excellent clinical response in several conditions with mild and transient adverse events. The results of this review suggest the safe and efficacious use of topical cantharidin in the field of dermatology and highlight the potential for future use.

Superficial leiomyosarcoma is a rare malignancy of muscular origin arising in the skin and soft tissues. Although wide local excision is the standard of care for these tumors, Mohs micrographic surgery is a promising treatment option as it provides for optimal margin control. The object of this systematic review is to examine the efficacy of micrographic surgery in the management of superficial leiomyosarcoma. A literature search was conducted using the PubMed/Medline and Cochrane databases; 14 studies representing 66 patients were included. Analysis demonstrated a notably low rate of recurrence (1.5%) and metastasis (0.0%) in tumors treated with micrographic surgery, contrasting with increased rates of recurrence and metastasis in tumors treated with wide local excision. These data may be influenced by a shortage of subcutaneous leiomyosarcoma in the included patients, as subcutaneous tumors are more likely to recur and metastasize. Further research is warranted to determine the value of Mohs micrographic surgery in treating superficial leiomyosarcoma and specifically, the subcutaneous variant.

Topical treatment with glucocorticosteroids is a mainstay therapy for many dermatologic conditions. Though efficacious in many, topical therapies often fail to achieve desired positive results in clinical practice. SKIN-CAP spray (Cheminova Laboratories International SA, Madrid, Spain), a product containing activated zinc pyrithione, and subsequently found to have contained clobetasol, provided unprecedented clearing of psoriasis even when ultra-high potency topical glucocorticosteroids had failed. A PubMed for terms related to corticosteroids, topical therapy, patient adherence, and SKIN-CAP spray was performed. Articles from 1997 to 2023 were included in the review of SKIN-CAP spray. In this review, we report the background of SKIN-CAP as well as studies that were performed in an attempt to explain its perceived high efficacy. The remarkable efficacy that occurred with SKIN-CAP over other delivery systems for high potency topical corticosteroids was initially speculated to be a consequence of an interaction between the zinc pyrithione and the clobetasol. However, no synergistic efficacy was identified, and there was no greater drug delivery. Better adherence to the SKIN-CAP product may explain the efficacy. The SKIN-CAP story provides insights into the need for healthy skepticism, the importance of treatment adherence, and ways to encourage better adherence to topical medications.

Climate change poses an increasing threat to human health, with well-documented impacts on dermatologic conditions. However, the U.S. healthcare sector is paradoxically a significant contributor to climate change-worsening greenhouse gas emissions. To address this negative externality, calls to action to decarbonize healthcare delivery have spurred research and initiatives around improving the environmental sustainability of medicine. Published sustainability recommendations for dermatologic practices have addressed themes such as renewable energy, single-use disposable materials, regulated medical waste, and clinician advocacy. Our current commentary provides an analysis of the potential of existing recommendations and outlines additional, novel, and actionable interventions. We highlight recently released decarbonization resources and regulatory changes. We emphasize the importance of reassessing procedure kits, minimizing medication waste, and implementing green procurement policies. We also address nuances in promoting environmentally-conscious transit, maximizing the efficient use of technology, supporting alternatives to single-use items, leveraging resources for patient education, assessing appropriate use of carbon credits, and bolstering community climate resilience.

The growing demand for dermatologic services and shortage of dermatologic providers sets the stage for favorable market conditions to open a private dermatology practice. However, business-related education in medicine is lacking and the concept of starting a new practice may be daunting for dermatologists in any stage of training. We describe key components of starting a private dermatology practice. Topics include strategies to build a business plan, find a location, explore financial options, structure a legal framework, and incorporate branding and marketing.

Enfortumab vedotin (EV) is a monoclonal antibody drug conjugate composed of antibody against nectin-4 and linked to the microtubule inhibitor monomethyl auristatin E that is used to treat metastatic urothelial carcinoma. Enfortumab vedotin-associated cutaneous adverse events are common and are clinically diverse, ranging from papulosquamous eruption to vesiculobullous eruptions such as Stevens-Johnson syndrome/toxic epidermal necrolysis and erythema multiforme-like eruption with vesiculobullae. Despite clinically diverse appearance, histopathology of EV-associated cutaneous adverse reactions often demonstrates interface dermatitis. We present the clinical and histopathologic features in a unique case of EV-associated widespread vesiculobullous eruption initially concerning for disseminated herpetic infection in a patient undergoing treatment of metastatic urothelial carcinoma with EV and pembrolizumab.

Bullous systemic lupus erythematosus (SLE) is a rare cutaneous manifestation of SLE characterized by sudden vesiculobullous eruptions. Herpes zoster infection may lead to rapid bullae development in patients with known bullous SLE. Herein, we describe a case of rapid development of bullous herpes zoster in a patient with bullous SLE. Patients with SLE and lupus nephritis exhibit an increased risk for herpes zoster infection. Bullous herpes zoster has been described in a previous patient with SLE and lupus nephritis. The current case illustrates that the presence of bullous SLE may have precipitated the development of bullous variant herpes zoster, as blisters leading to breakages in the skin increase risk for superinfection by viral pathogens. The current case highlights the importance of monitoring for skin changes in patients with SLE and maintaining a low threshold for infectious workup. Furthermore, it is important to recognize that the presence of bullae in SLE may confuse the diagnosis of bullous herpes zoster, leading to delays in diagnosis and management. Given high rates of morbidity and mortality in disseminated herpes zoster infection, the emergence of bullae in patients with SLE should raise a high index of suspicion for herpes zoster infection and prompt systemic workup.

Acquired reactive perforating collagenosis is an uncommon disorder that present as keratotic plugs on the skin owing to transepidermal perforation of dermal connective tissue. Etiology is unclear, although the condition has been associated with renal disease, diabetes, and HIV. It can frequently be misdiagnosed and lead to significant impact on quality of life, particularly in patients with skin of color. Herein, we present an skin of color patient with this condition who experienced severe pruritus over years before receiving a definitive diagnosis. Clobetasol improved her condition and quality of life over several months.

Blastomyces dermatitidis is a dimorphic fungus that can disseminate in the immunocompetent and immunodeficient. Many infected patients display heterogenous cutaneous findings, making it one of dermatology's great clinical mimics. Cases presenting as single lesions are often mistaken for neoplasms or other infections. We report a patient with diabetes mellitus who presented to the emergency department with a two-month history of an ulcerated jawline nodule. Treatment with incision/drainage and doxycycline for presumed bacterial abscess was unsuccessful. Upon re-presentation 10 days later, biopsy and fungal culture of the tumor confirmed infection with B. dermatitidis. Chest computed tomography revealed disease dissemination. Halfway through a 6-month course of itraconazole, cutaneous and pulmonary findings were notably improved. Diabetes is an emerging risk factor for dissemination that likely contributed to the severity in our case. Early biopsy can prevent potentially life-threatening treatment delays, highlighting the need for blastomycosis to be considered in the differential diagnosis of non-healing wounds.

We present a patient with human immunodeficiency virus who developed multiple painful lesions that previously in the past had speciated as Cryptococcus neoformans cutaneously, and in the lung. Despite induction therapy for presumed re-infection, the patient did not improve so a biopsy was performed and this was speciated as Mycobacterium avium complex, with final diagnosis being disseminated Mycobacterium avium complex. This case highlights the importance of considering a broad differential diagnosis for any new lesions regardless of prior culture data.

A 68-year-old woman with a history of seizures on cenobamate presented with an itchy rash all over her body. The rash started about one month prior to her presentation to the dermatology clinic. The rash was initially treated with topical triamcinolone with improvement at one-month follow-up. However, four months later the rash flared and there was concern that cenobamate was the cause. Biopsy was performed showing vacuolar interface dermatitis with atrophy, suggestive of subacute lupus erythematosus. Blood work revealed positive antinuclear antibody, anti-ribonucleoprotein antibody, Sjogren Anti-SS-A and positive histone antibody. Given the worsening rash, positive labs, and cenobamate as the only changed drug several months before initial onset, she was diagnosed with drug-induced subacute cutaneous lupus erythematous and her cenobamate was discontinued. To the best of your knowledge, this is the first reported case of a medication in the carbamate family leading to drug induced subacute cutaneous lupus erythematosus.

Lichen planus pigmentosus (LPP) is recognized as a rare variant of lichen planus, characterized by dermal hyperpigmentation. Specifically, a particular intertriginous variant of LPP is known as lichen planus pigmentosus inversus (LPPI). In our case, the patient presented with symmetric, hyperpigmented dark brown patches mainly in axillary areas, closely resembling the features of acanthosis nigricans (AN). The differential diagnosis considered included LPPI, AN, post-inflammatory hyperpigmentation related to contact dermatitis, symmetrical drug-related intertriginous and flexural exanthema, fixed drug eruption, and erythema dyschromicum perstans (EDP). Histopathological examination revealed the absence of hyperkeratosis and papillomatosis, typically associated with AN. Dermoscopy revealed diffuse brownish hue along with dots and globules of inconsistent size, which suggests dermal pigmentary incontinence and the likelihood of LPPI. This case illustrates the challenge in differentiating LPPI from similar flexural hyperpigmentation disorders based on the comprehensive approach including thorough history taking, clinical manifestations, histopathological analysis, and dermoscopic examination.

Drug hypersensitivity syndrome or DRESS (drug reaction with eosinophilia and systemic symptoms) is a severe reaction with an estimated mortality of 10%. Antibacillary drugs are rarely incriminated. A 28-year-old patient with tubercular miliaria who developed antibacillary-induced DRESS is presented. The dermatological lesions appeared four weeks after the beginning of the antitubercular treatment. The diagnosis of DRESS was made when all the Registry of Severe Toxidermia (RegiSCAR) criteria were present. The treatment was stopped and the patient was put on symptomatic treatment under supervision in the intensive care unit, with progressive improvement. Substitution with second-line antituberculosis drugs was necessary and was done with caution. DRESS with antituberculosis drugs is rare and its management is not codified.

Paracoccidioidomycosis is a systemic fungal disease with a highly variable distribution, endemic to Central and South America with the highest prevalence in Brazil, Argentina, and Colombia. The chronic presentation of the disease is commonly observed in adult men and they manifest with pulmonary and mucocutaneous lesions. We report a fatal case of disseminated paracoccidioidomycosis in a 68-year-old immunocompetent man, with pulmonary, skin, mucosal, and cerebral involvement. Mucocutaneous lesions were decisive for the etiological diagnosis.

Subcutaneous fat necrosis of the newborn is a disease affecting neonates in the first weeks to months of life. It is characterized by dermal edema and underlying fat necrosis, typically presenting with firm, erythematous subcutaneous plaques and nodules, often located on the shoulders, back, buttocks, thighs, and extremities. We report an unusual presentation of liquefactive subcutaneous fat necrosis of the newborn in a two-week old term infant. The neonatal period was complicated by respiratory failure requiring intubation and severe encephalopathy. After completion of therapeutic hypothermia, the patient developed fluctuant and liquefactive nodules on her back. The neonate also had initial hypocalcemia that required treatment and then developed hypercalcemia, that resolved without intervention. The nodules and plaques on her back persisted into the first year of life and then gradually started to improve when she was 13 months old.

Adiposis dolorosa (Dercum disease) is a rare condition characterized by diffuse and recurring painful lipomas on the trunk and extremities. Patients are typically middle-aged females with an elevated BMI presenting with chronic pain. Physical examination reveals soft subcutaneous nodules and masses, tender to palpation. The associated pain significantly impacts quality of life and requires therapeutic intervention. The most common treatment option is surgical excision. Alternative options should be considered for patients with numerous lipomas where surgical management is not practical or is not desired. Deoxycholic acid injections are a viable alternative non-surgical technique. We present a case of a 55-year-old woman who presented with a history of Dercum disease and worsening pain associated with multiple lipomas. The patient desired a non-surgical intervention. She was subsequently treated with three rounds of deoxycholic acid injections with reduction in pain and improved mobility. Intralesional deoxycholic acid injections are a safe and effective nonsurgical alternative for patients with multiple lipomas.

Herein we present a 48-year-old man who was diagnosed with a nodular basal cell carcinoma (BCC) of the left chin that was revealed on Mohs frozen sections to be a rippled-pattern BCC with invasion into muscle and necessitated interdisciplinary care for concern for a concurrent salivary gland carcinoma. Rippled-pattern BCC has been documented in fewer than ten cases, though this may also be attributed to confusion regarding nomenclature. Microscopically, rippled-pattern BCC exhibits distinctive features that differentiates it from other patterns. The tumor cells form interconnected networks or cords with intervening mucinous spaces within a fibrotic stroma resulting in a rippled appearance. As they are generally considered nodular BCCs, management of rippled-pattern BCCs can involve surgical excision, Mohs micrographic surgery, or other appropriate treatment modalities based on the tumor's location, size, and degree of invasion.`

Wolf isotopic response refers to a new skin disorder manifesting in the area of a previous skin lesion that has healed. A variety of disease processes and dermatoses have been described that evoke an isotopic response. We report a man with metastatic hepatocellular carcinoma who received palliative radiation and later experienced a pembrolizumab-induced lichenoid dermatitis at the same site of radiation, representing a cutaneous immune-related adverse event displaying an isotopic response.

Soft tissue chondroma is a rare benign tumor that occurs more often in the distal limbs and is unattached to the underlying bone. An 11-year-old boy, presented with a nodule of the subungual area of the right big toe. Objectively, the nail plate was partially destroyed owing to protrusion. Digital dermoscopy revealed yellow keratinous masses in the subungual area, with fibers adhering to the surface. Post-traumatic hemorrhages were observed in the tumor. Owing to functional discomfort, the patient underwent removal of the mass under local anesthesia. The histological picture is consistent with subungual soft tissue chondroma. Subungual soft tissue chondroma is more common in adults, but can affect people of all ages.

Solar elastosis is a form of photoaging theorized to result from long-term exposure to ultraviolet radiation. Clinically, solar elastosis manifests as yellow, atrophic, rhytid skin with a leathery appearance, most commonly affecting sun-exposed areas such as the face, neck, chest, or arms. Owing to its well-documented association with an elevated risk of skin cancer, recognizing the presence of solar elastosis is essential for clinicians. In this case, we evaluate a presentation of solar elastosis confined strictly to the perioral region, sparing the remainder of sun-exposed facial areas.