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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 23, Issue 7, 2017


The role of interleukin-17 in the pathogenesis of hidradenitis suppurativa

Hidradenitis suppurativa is a chronic inflammatory skin condition affecting primarily the axillary, perianal, and inguinal areas. Patients with hidradenitis suppurativa present with occlusion and subsequent rupture of follicular ducts, profound abscesses, fistulae, odorous discharge, fibrosis, and scar formation, causing significant morbidity. Knowledge of the pathogenesis of hidradenitis suppurativa is limited and treatment with antimicrobial drugs, immunosuppressants, and surgical procedures have shown varying results. The pathogenic role of the interleukin-17 cytokine family in chronic inflammatory skin conditions has been described. Interleukin-17A and interleukin-17F have similar properties and induce the production of cytokines, chemokines, antimicrobial peptides, and metalloproteinases, all of which take part in the inflammatory response. The efficacy of anti-interleukin-17A therapy in psoriasis has also been proven and anti- interleukin-17A drugs are already in use for this condition. There is currently no consensus on the role of interleukin-17 in the pathogenesis of hidradenitis suppurativa. Studies have demonstrated increased interleukin-17 mRNA expression in lesional hidradenitis suppurativa skin, whereas the protein concentrations of interleukin-17 were found to be normal compared to healthy control skin in one other study. A phase II clinical trial on anti- interleukin-17 therapy in hidradenitis suppurativa is ongoing.


Dermatology on Reddit: elucidating trends in dermatologic communications on the world wide web

Platforms of social media, including the website Reddit, have become increasingly popular sites for users to communicate medical information. A study investigating dermatology content on Reddit has not been performed in the current literature. The purpose of this study is to enumerate the dermatology subreddits, quantify subscribers, and characterize posts to estimate the presence of dermatology-related content on Reddit. A Reddit search of the fourteen most common skin diseases globally was performed. Additionally, the terms “dermatology”, and “skin” were searched in order to identify more subreddits relevant to the field. Dermatology-related subreddits that had ≥1000 subscribers were evaluated for content and categorized for analysis. We identified 38 subreddits related to dermatology with subscriber numbers ranging from 52 to 209,973. For 17 of the 38 subreddits that were further analyzed, most posts fell under the category of “seeking health/cosmetic advice.” Reddit serves as a communication stage for individuals to discuss, engage, and connect on dermatologic topics. Furthermore, the platform offers an opportunity for medical professionals to distribute evidence-based information concerning dermatologic conditions.

Dermatology on Snapchat

Launched in 2011, Snapchat is one of the newest social media platforms with over 158 million active daily users. This study investigated the presence of dermatology-related content on Snapchat. We searched for Snapchat accounts for the top ten most popular dermatology journals, professional dermatological organizations, and dermatology-related patient advocate groups on social media. None of the above-mentioned entities were found on Snapchat. Plastic surgeons were found to primarily utilize the application, although one prominent dermatologist was also found. It was theorized that the brevity of the “snaps” was a contributing factor for dermatological organizations to not use the application. However, Snapchat in the right practice setting may be useful for dermatologists, not only to educate followers, but also as a marketing tool to Millennials.

Case Report

Cutaneous Balamuthia mandrillaris infection as a precursor to Balamuthia amoebic encephalitis (BAE) in a healthy 84-year-old Californian

Soil and freshwater-dwelling amoebae may opportunistically infect the skin and evoke a granulomatous dermatitis that camouflages their underlying morphology. Amoebic infestations are incredibly rare in the U.S., predominantly occurring in the young, elderly, and immunocompromised. Sadly, because diagnosis is difficult and unsuspected, most cases are diagnosed at autopsy. The following case is of a healthy 84-year-old man with a non-healing nodulo-ulcerative cutaneous lesion on his left forearm that appeared following a gardening injury. Lesional punch biopsies repeatedly showed non-specific granulomatous inflammation with no pathogens evident histologically or by culture. Histopathologic diagnosis was made five months after initial presentation via identification of amoebic trophozoite forms in tissue from a large excisional specimen. Anti-amoebic therapy was initiated immediately. The patient experienced mental status changes three days following lesion excision, with evidence of a cystic mass in the left medial parieto-occipital lobe by CT. Both intraoperative brain biopsies and cutaneous tissue samples tested positive for Balamuthia mandrillaris by indirect immunofluorescent antibody assay performed at the Centers for Disease Control. The patient achieved a full recovery on a triple antibiotic regimen. Clinical suspicion and thorough histopathologic analysis may determine the difference between survival and death for a patient presenting with a treatment-refractory localized granulomatous lesion.

Adalimumab-related alopecia in a patient affected by psoriasis

Alopecia induced by biological therapy is a rare side effect of this type of drugs. A total of 23 patients of psoriasiform eruptions with severe scalp involvement that induced alopecia during anti-tumor necrosis factor (anti-TNF) treatment of non-dermatological conditions have been previously reported. We present a 50-year-old man affected by plaque psoriasis that developed psoriasiform patches with alopecia over his scalp 10 months after initiating treatment with adalimumab. Punch biopsy of the alopecic area on the scalp revealed psoriasiform epidermal changes and alopecia areata-like dermal changes. Along with these findings, there was a dermal inflammatory infiltrate made up of eosinophils and plasma cells. In conclusion, scalp psoriasiform lesions with alopecia in patients treated with anti-TNF agents have been rarely reported. We describe a patient with anti-TNF therapy-related alopecia affected by psoriasis. Our patient has a peculiar histology with features of psoriasis and alopecia areata in addition to eosinophils and plasma cells. This entity may respond to topical treatment. However in patients of severe scalp involvement anti-TNF suspension should be considered.

Generalized bullous fixed drug eruption imitating toxic epidermal necrolysis: a case report and literature review

Fixed drug eruption (FDE) is defined as sharply demarcated erythematous patches or plaques that occur secondary to systemic exposure to a causative medication. Eruptions are deemed “fixed” because upon repeated exposure they recur at previously affected sites. Generalized bullous fixed drug eruption (GBFDE) is a rare FDE variant occurring in patients with a previous history of FDE. Given the extensive cutaneous involvement and the frequent mucosal ulcerations associated with GBFDE, it is challenging to discern these lesions from Steven-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). The presence of significantly elevated lesional and serum granulysin in SJS/TEN is an important discriminating factor because granulysin levels remain significantly lower in GBFDE. The implementation of an immunochromatographic test for rapid detection of elevated granulysin levels could therefore facilitate the early diagnosis of SJS/TEN. We report a case of GBFDE to elucidate the characteristic differences in clinical presentation, histopathology, and immunohistochemistry that can facilitate diagnosis.

Case Presentation

Acquired bullous acrodermatitis enteropathica as a histologic mimic of pemphigus foliaceus in a patient on parenteral nutrition

Acquired zinc deficiency can develop as a consequence of poor nutritional intake or from dependence on total parenteral nutrition. Acquired zinc deficiency dermatitis classically manifests with erosions and scaly plaques in a periorificial and acral distribution. We present a case of a woman on parenteral nutrition who presented with bullous acrodermatitis mimicking pemphigus foliaceus histopathologically. This case highlights clinical and histopathologic variants of zinc deficiency that may lead to a delay in diagnosis.

Mycophenolate mofetil as a successful therapy for idiopathic granulomatous mastitis

Idiopathic granulomatous mastitis (IGM) is a benign chronic inflammatory breast disease of unknown etiology. No consensus exists as to the best therapeutic approach, though treatment choices include antibiotics, drainage, surgical excision, steroids, methotrexate, and observation. Herein we report a case of idiopathic granulomatous mastitis that was refractory to methotrexate and intralesional and systemic steroids but responded well to mycophenolate mofetil 1500mg twice daily. To our knowledge, this is the first report of the effective use of mycophenolate mofetil in idiopathic granulomatous mastitis.

Crystalline folliculitis revealed by non-aqueous staining technique

Necrotizing infundibular crystalline folliculitis (NICF) is a rare superficial folliculitis characterized by expansive deposits of birefringent crystallized lipid. We report a case of NICF in a transplant patient presenting with folliculocentric acneiform papules across the lateral face and neck. Biopsy demonstrated intrafollicular crystalline deposits within an intact epidermis. Diagnostic crystals were identified using a non-aqueous histologic technique involving thick unstained sections. To our knowledge, this is the first report of NICF in a transplant patient. Our case suggests NICF is a follicular disorder and highlights a technique that may prevent loss of birefringent crystals and assist in facilitating accurate diagnosis.

Disseminated cutaneous sporotrichosis presenting as a necrotic facial mass: Case and review

Sporotrichosis is a subcutaneous mycotic infection caused by Sporothrix schenckii, a group of common saprophytes of soil, plants, and organic debris. Disseminated forms may be seen in the setting of immunosuppression and are typically treated initially with intravenous lipidized amphotericin B. We report an unusual case of a 65-year-old woman who developed disseminated cutaneous sporotrichosis with extensive facial involvement in the absence of a known primary inoculation. Her cutaneous lesions completely resolved after treatment with intravenous posaconazole without amphotericin B.

Infantile bullous pemphigoid with “string of pearls sign”

Bullous pemphigoid (BP) is an immune mediated bullous disease that is manifested by urticarial plaques with superimposed subepidermal blisters and significant pruritus. It is generally found in the elderly, but is rare in the pediatric population. A 5-month-old girl previously diagnosed with hand-foot-mouth disease was examined in our dermatology department owing to vesicles and bullae, initially located to the hands and feet, which progressed with new lesions. Tense vesicles and bullae distributed in an annular string of pearls pattern on the abdomen and facial and cervical regions were noted. Histologic and immunologic findings were consistent with the diagnosis of infantile BP. Disease control was obtained with oral prednisolone and dapsone; the patient was still in clinical remission 6 months after treatment cessation. The differential diagnosis of the clinical presentation of the lesions in our patient is of note, given that this blistering pattern is frequently reported in association with linear IgA bullous dermatosis.

A pediatric case of unusual melanocytic proliferation of the nail

Pigmentation of the nail plate, or melanonychia, is typically a benign condition caused by melanocyte activation. Although rare, melanonychia may be the initial presentation of melanoma, thus all cases require an in-depth examination. Evaluation in pediatric patients can prove especially difficult as benign cases have a higher prevalence of atypia compared to adults. Lack of specific treatment guidelines in the pediatric population can make diagnosis and treatment challenging. We report a pediatric patient with melanonychia with atypical features that required significant evaluations and collaboration to ultimately reach a treatment plan.

Congenital juvenile xanthogranuloma with ulceration: a pediatric case report

Congenital juvenile xanthogranuloma (JXG) is an uncommon diagnosis and even more rarely presents with ulceration. We report such a case in a two-week-old girl. Biopsy was performed to rule out any concerning entities. Adequate treatment was provided with topical petrolatum and occasional miconozole or zinc oxide; the mass spontaneously regressed. Because congenital JXG has an excellent prognosis, insight into unique presentations such as this may provide useful information and avoid unnecessary surgical interventions.

Herpes zoster ophthalmicus with associated vasculopathy causing stroke

Varicella zoster virus (VZV) is an exclusively human, double-stranded DNA virus. Primary infection causes varicella (chickenpox); later the virus becomes dormant in the dorsal root, cranial nerve, and autonomic ganglia along the entire span of the nervous system, retaining the capacity to reactivate and cause a variety of dermal and neurological complications. Recently there has been increasing recognition, both clinically and epidemiologically, of the relationship between VZV and subsequent strokes. Herein, we describe a case of a previously healthy individual with reactivation of VZV causing herpes zoster opthtalmicus along with devastating multifocal vasculopathy. It is crucial for dermatologists to recognize the dermatomal vesicular eruption in this high risk area to aid in prompt diagnosis in an effort to improve clinical prognosis.

Alopecia universalis unresponsive to treatment with tofacinitib: report of a case with a brief review of the literature

Janus kinase inhibitors are emerging treatment alternatives in various immune-mediated diseases including alopecia universalis. Herein, we report a patient with psoriasis and alopecia universalis in whom treatment with tofacitinib led to remission of psoriasis without improvement in alopecia universalis. Despite the promising potential in alopecia areata treatment, research evaluating the efficacy of different Janus kinase inhibitors and possible prognostic factors related with a more favorable response are warranted.

Photo Vignette

Retronychia: an underdiagnosed disease

Retronychia is a recently described cause of ingrowth of the nail plate on the ventral surface of the proximal nail fold. Clinical features are repeated episodes of proximal paronychia, nail plate thickening, and occasionally granulation tissue emergence. The usual treatments for paronychia such as antibiotics and antifungals are ineffective in these cases. Avulsion of the nail plate is the treatment of choice for these patients, but effective treatment is usually delayed owing to inadequate diagnosis. Herein, we describe a 28-year-old woman with a case of retronychia. She was treated for two months with oral and topical antifungal and antibiotics by her general practitioner. After proper diagnosis and avulsion of the nail she presented a normal and non-painful growth of the affected nail.

Annular elastolytic giant cell granuloma: a “visible” diagnosis

Annular elastolytic giant cell granuloma (AEGCG) is a rare granulomatous skin disease of undetermined cause, characterized by annular plaques with raised erythematous borders in sun-exposed skin. The typical histologic features are dermal infiltration by multinucleated giant cells, elastin degeneration, and elastophagocytosis. The authors describe a clinical case of AEGCG, which exhibited an excellent response to hydroxycloroquine.


Ustekinumab to target granulomatous dermatitis in recalcitrant ulcerative necrobiosis lipoidica: case report and proposed mechanism

We present a 42-year-old woman with no history of diabetes or glucose intolerance who had a 5-year history of ulcerative necrobiosis lipoidica (NL). Despite failure of multiple medications, she experienced clearing of her ulcers after her treatment was changed to ustekinumab. We discuss our patient’s disease course and elaborate upon mechanistic reasons for her improvement related to ustekinumab therapy.

Congenital isolated leukonychia

Congenital leukonychia is a rare nail disorder that may occur in isolation or in association with a number of syndromic disorders. In the following letter, we describe a case of isolated congenital true leukonychia to add to the current literature. This case is particularly unique in that it does not appear to be inherited in an autosomal dominant fashion, in contrast to the majority of reported cases.

Value of dermoscopy for the diagnosis of monilethrix

Monilethrix is a rare genodermatosis characterized by a hair shaft dysplasia responsible for hypotrichosis. We report the case of a child with monilethrix with no associated cases in the family. Trichoscopy facilitated the diagnosis. A 2-year-old boy presented with diffuse alopecia and persistent fragile hair for several months. Clinical examination revealed alopecia with hairs broken several millimeters from the scalp. Trichoscopy revealed zones of dystrophic constriction of the hair shaft, separated at regular intervals by elliptical nodes of normal thickness, giving a “necklace” appearance. The diagnosis of monilethrix was made on the basis of these specific features. The diagnosis of monilethrix was more difficult to establish in our patient owing to the absence of any familial cases.