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Open Access Publications from the University of California

Dermatology Online Journal

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Dermatology Online Journal is an open-access, refereed publication intended to meet reference and education needs of the international dermatology community since 1995. Dermatology Online Journal is supported by the Department of Dermatology UC Davis, and by the Northern California Veterans Administration.

Volume 26, Issue 2, 2020


The role of hypothalamus-pituitary-adrenal (HPA)-like axis in inflammatory pilosebaceous disorders

Skin is the largest peripheral endocrine organ and functions as a hormone target and endocrine gland. A cutaneous hypothalamus-pituitary-adrenal (HPA)-like axis enables the skin to respond to stress and regulates its steroidogenic activity. The pilosebaceous unit is a site for production and metabolism of a number of steroid hormones, including stress and sex hormones. This is an overview of the important role that the cutaneous HPA-like-axis plays in the pathogenesis and treatment of inflammatory pilosebaceous disorders, including acne, rosacea, seborrheic dermatitis, and hidradenitis suppurativa.


Gram-negative infections in patients with folliculitis decalvans: a subset of patients requiring alternative treatment

Background Folliculitis decalvans is a neutrophilic cicatricial alopecia whose etiology remains unknown. It is frequently associated with staphylococcal infections. We aimed to determine the rate of gram-negative infections in patients with folliculitis decalvans. Methods A retrospective chart review was performed of patients with biopsy-proven folliculitis decalvans seen at a tertiary hair referral center. The results of bacterial cultures were evaluated. Subjects were determined to have no infection, gram-positive infections, gram-negative infections, or mixed infections. Results Thirty-nine subjects were included in the study. Ninety-three cultures were performed. The majority of cultures were positive for staphylococci. Eleven patients (28%) had gram-negative infections of the scalp. Gram-negative infections comprised one-third of all cultures (33%). Conclusion We present the largest cohort of folliculitis decalvans patients with gram-negative infections, suggesting the need for routine bacterial cultures in patients who are not responsive to standard anti-staphylococcal antibiotics. Awareness of the incidence of these infections may lead to better therapeutic outcomes.


The use of drug calendars for the diagnosis of cutaneous drug eruptions in the age of electronic medical records

A morbilliform drug eruption is the most common condition leading to a dermatology consultation for a patient in the hospital. Timing is an important diagnostic tool since the onset of a skin rash usually takes place within days-to-weeks of the start of the implicated drug. A comprehensive, thorough, and reliable drug history by the clinician is essential. Therefore, to assist in the task of determining the causative medication of a new skin rash in a hospitalized patient, the creation of a drug calendar is recommended. The development of an electronic version of the drug calendar offers several benefits over the manual version. As the use of electronic medical records continues to become the standard in medicine, the electronic drug calendar will serve as an invaluable tool for the diagnosis of drug hypersensitivity.

Case Report

Follicular occlusion triad: an isotopic response or adverse effect of rituximab?

Follicular occlusion triad is a symptom complex of three conditions with a similar pathophysiology including hidradenitis suppurativa (HS), dissecting cellulitis of the scalp, and acne conglobata. Although the exact pathogenesis of the triad is unknown, it appears to be related to follicular occlusion in areas with apocrine glands. Wolf isotopic response refers to the occurrence of a new dermatosis at the site of another, unrelated, previously healed dermatosis. We present a 26-year-old man with a history of pemphigus foliaceus (PF) who developed large draining nodules with scarring and sinus tracts, compatible with follicular occlusion triad, preferentially at areas previously affected by PF thirteen months after treatment with rituximab. To the authors' knowledge there are no reported cases of follicular occlusion triad or HS manifesting as an isotopic response. However, one member of the triad, HS, has been reported to occur infrequently following the use of biologic agents such as adalimumab, infliximab, tocilizumab, and rituximab for chronic immune-mediated inflammatory diseases (psoriasis, Crohn disease, rheumatoid arthritis, and ankylosing spondylitis).

Nevus sebaceus with syringocystadenoma papilliferum, prurigo nodularis, apocrine cystadenoma, basaloid follicular proliferation, and sebaceoma: case report and review of nevus sebaceus-associated conditions

Nevus sebaceus is a benign skin hamartoma of congenital onset that grows during puberty, and in adulthood can develop secondary benign and malignant neoplasms. The most common benign neoplasms occurring in nevus sebaceus are believed to be syringocystadenoma papilliferum, trichilemmoma, and trichoblastoma. A patient with nevus sebaceus developed not only syringocystadenoma papilliferum but also prurigo nodularis within her hamartomatous lesion; multiple biopsies were necessary to establish the diagnoses. Excision of the residual nevus sebaceus also revealed an apocrine cystadenoma, basaloid follicular proliferation, and sebaceoma. Also, it is important to select the appropriate biopsy site and size when evaluating a patient for secondary neoplasms within their nevus sebaceous. Indeed, more than one biopsy may be required if additional diagnoses are suspected.

Case Presentation

Transient acantholytic dermatosis in a patient with prostate cancer

Transient acantholytic dermatosis (TAD) is a relatively common entity that has been also noted to occur in patients with cancer. Herein, we describe a case of transient acantholytic dermatosis occurring in a patient with a history of prostate cancer status post radiation, now being treated with combination therapy with pembrolizumab and carboplatin-pemetrexed for advanced lung adenocarcinoma. Our case emphasizes the importance of being cognizant of TAD and its associations, particularly in cancer patients.

Thiotepa hyperpigmentation preceding epidermal necrosis: malignant intertrigo misdiagnosed as Stevens-Johnson syndrome-toxic epidermal necrolysis overlap

Thiotepa is a common alkylating agent known to precipitate cutaneous reactions consistent with toxic erythema of chemotherapy, including erythema and hyperpigmentation. Herein, we describe an atypical case of malignant intertrigo involving preferential erythema and desquamation not only of skin folds but also of occluded areas after thiotepa-based conditioning. The diagnosis was complicated by concurrent stomatitis and oral petechiae in the setting of autologous stem cell transplant 11 days prior for diffuse large B-cell lymphoma. Histopathological examination from two cutaneous sites demonstrated epidermal dysmaturation and eccrine gland necrosis consistent with thiotepa-induced desquamation and not Stevens-Johnson syndrome or graft-versus-host-disease. Malignant intertrigo can present with extensive cutaneous involvement, as evidenced by our patient who had 25% body surface area affected. Mucosal involvement is common with most chemotherapeutic regimens and its presence should not deter the astute clinician from consideration of a diagnosis of toxic erythema of chemotherapy. No further interventions were needed and the patient healed spontaneously.

A patient with anti-NXP2-positive dermatomyositis and syphilis

Dermatomyositis is an auto-immune inflammatory myopathy that primarily affects the skin and muscle and can be triggered by exposure to various environmental factors. We present a patient with active syphilis infection who developed dermatomyositis and discuss the significance of anti-NXP2 autoantibody positivity.

BRAF inhibitor and hairy cell leukemia-related transient acantholytic dermatosis

Grover disease (GD) is an acquired, nonfamilial, nonimmune mediated, transient or persistent acantholytic dermatosis. Herein, we present a 72-year-old man who had clinical and histopathologic findings of GD following two weeks of treatment with vemurafenib without MEK inhibitor. The patient was successfully treated with topical emollients and a high-potency corticosteroid. Meanwhile, vemurafenib was temporarily discontinued. Drug-induced GD has increasingly been reported in patients on BRAF inhibitor monotherapy as an immune-related adverse event. The cutaneous side effects seem to arise secondary to a paradoxical activation of the mitogen-activated protein kinase signaling of BRAF inhibitor treatment, leading to keratinocyte proliferation. Although the pathogenesis of GD has not been delineated, there is suggestion of activation of T lymphocytes, particularly helper cells under the action of pro-inflammatory cytokines, resulting in proliferation of keratinocytes. Combination therapy with a MEK inhibitor appears to prevent BRAF-induced GD. Given that there is a higher prevalence of GD in patients with hematologic malignancy, a direct causal relationship between the initiation of vemurafenib therapy and development of GD in this case may be difficult to establish.

Violaceous nodules in an HIV-positive man

Plasmablastic lymphoma (PBL) is a rare and aggressive malignancy associated with immunosuppression and the oncogenic effects of the Epstein-Barr virus (EBV). We present an HIV-positive man with PBL that presented as ulcers and violaceous exophytic nodules on the legs. The clinical features, histologic appearance, and differential diagnosis of this malignancy are briefly reviewed.

A case of atypical disseminated herpes simplex virus 1 with hepatitis in a liver transplant recipient: the need for dermatologic evaluation

Disseminated herpes simplex virus (HSV) is mainly seen in immunocompromised individuals. Atypical lesions can be present in both primary infection and reactivation disease. Compared with the general population, inmunocompromised hosts are at greater risk of increased persistency and severity of clinical manifestations, including severe systemic involvement such as esophagitis, meningitis, and hepatitis. Herein, we report the case of a liver transplant recipient with atypical disseminated herpes simplex virus-1 complicated by HSV-related hepatitis. Dermatological consultation and histological assessment were crucial for a correct diagnosis and treatment.

Photo Vignette

Adult-onset porokeratotic eccrine ostial and dermal duct nevus:dermatoscopic findings and treatment with tazarotene

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare dermatosis initially described as ‘comedo nevus’ and renamed ‘PEODDN’; it has also been referred to as linear eccrine nevus with comedones, porokeratotic eccrine ostial and hair follicle nevus, and porokeratotic adnexal ostial nevus. PEODDN is usually present at birth or develops early in life. Rarely, PEODDN can develop in adults. The treatment of this puzzling condition is not standardized. We report herein a new case of adultonset PEODDN with dermatoscopic images. Our patient responded favorably to topical tazarotene.

A case of tinea incognito mimicking subcorneal pustular dermatosis

An 89-year-old woman presented with plaque-like lesions, accompanied with pustules and desquamation on the back and front of the trunk for approximately one year. Long term use of potent topical corticosteroids was ineffective. Because of the chronicity of her condition, the diagnoses of subcorneal dermatosis or subcorneal pustular dermatosis type of IgA pemphigus were considered. However, fungal hyphae were observed in the potassium hydroxide examination. Therefore, we present this case since this clinical appearance of tinea incognito can also mimic various pustular dermatoses.

Erythema nodosum induced by oral isotretinoin in a patient with condylomata acuminata

Erythema nodosum (EN) is a form of septal panniculitis, which is believed to represent a delayed hypersensitivity reaction activated by infectious agents, drugs, granulomatous and autoimmune diseases, pregnancy, and malignancies. There are only four reported cases of EN during oral isotretinoin therapy to our knowledge, all of them occurring in patients with severe acne. Since acne itself can trigger EN, the question as to whether there is indeed a causative relationship between isotretinoin and EN in the reported cases remains to be elucidated. We present herein a 20-year-old woman with multiple vulvar condylomata acuminata who developed EN two weeks after onset of oral isotretinoin therapy. To the best of our knowledge, this is the first report of EN occurring during isotretinoin treatment in a patient without acne and strongly indicates that the pathogenesis of EN can be directly related to the biological actions of isotretinoin. Erythema nodosum should be regarded as a rare side effect of oral isotretinoin therapy, regardless of the underlying disease. Physicians should be aware of this rare side effect.

A case of eosinophilic fasciitis and generalized morphea overlap

A 60-year old man developed skin hardening and edema on his extremities. Although he had been treated with oral prednisolone at another hospital, skin stiffness relapsed during tapering of prednisolone. At the initial visit to our department, physical examination showed skin hardening of the extremities and also symmetric erythematous macules on the back. Histological examination revealed fasciitis on the forearm and morphea on the back. Eosinophilic fasciitis is occasionally associated with morphea. However, cases of concurrent eosinophilic fasciitis and generalized morphea are rare. In the present case, CD34 was differentially expressed in both lesions, suggesting eosinophilic fasciitis and morphea are separate diseases with different origin of mesenchymal cells.

A unique case of prurigo pigmentosa related to ketogenic diet

Prurigo pigmentosa is a rare inflammatory dermatosis that primarily affects Japanese patients. Various triggers have been identified, including the ketogenic diet. Given the current popularity of the ketogenic diet, the incidence of prurigo pigmentosa may be on the rise. Herein, to the best of our knowledge, we present the first case of prurigo pigmentosa reported in a Hispanic patient in the United States.

Skin involvement as the presenting sign of a male breast cancer

Male breast cancer is a rare disease with an unknown etiopathogenesis. We report a case of a 50-year-old man with a breast cancer revealed by skin involvement.


Bullous aplasia cutis congenita: A rare presentation of a rare disease

Aplasia cutis congenita (ACC) is a congenital disorder characterized by localized or generalized absence of skin. Bullous aplasia cutis congenita (BACC) is a rare clinical subtype that has few documented reports in the literature. Herein, we present a new case of BACC in which the bulla was unruptured at birth.


Long-term follow-up of 22 psoriatic patients treated with ixekizumab after failure of secukinumab

The original article was published on February 15, 2020 and corrected on March 26, 2020.

The revised version of the article amends the table and figure, while leaving the text largely unchanged. The changes appear in the revised online PDF copy of this article.