[Dissecting cellulitis of the scalp: a retrospective study of 7 cases confirming the efficacy of oral isotretinoin]. / Cellulite disséquante du cuir chevelu: étude rétrospective de 7 cas confirmant l'efficacité de l'isotrétinoïne per os.

BACKGROUND: Dissecting cellulitis of the scalp (DCS) is a rare and long-standing disease and its aetiopathogenesis remains unclear. Various therapeutic alternatives exist. We attempted to assess the efficacy of oral isotretinoin in a series of patients. PATIENTS AND METHODS: Seven cases of DCS followed and treated by one of the authors at the Sabouraud Centre in the Saint-Louis Hospital between 2007 and 2013 were retrospectively studied and the efficacy of oral isotretinoin was evaluated. RESULTS: The seven patients included were males aged between 22 and 39 years, with alopecic nodules on the occiput (two cases) or the top of the vertex (five cases). Most patients were given oral isotretinoin at a dosage of 0.75mg/kg/day for at least nine months. The outcome was satisfactory with complete healing of the lesions and good regrowth in all cases. Follow-up after recovery lasted between 16 and 42 months. CONCLUSION: Based on published studies and the results of the present study, oral isotretinoin at a dose of 0.75mg/kg/day may be proposed as first-line treatment for DCS.

[Two new trichoscopic signs in alopecic and aseptic nodules of the scalp: "Eastern pancake sign" and comedo-like structures]. / Deux nouveaux signes trichoscopiques dans les nodules alopéciques et aseptiques du cuir chevelu : le « signe de la crêpe orientale ¼ et les structures comédoniennes.

BACKGROUND: The purpose of this study is to describe two new trichoscopic signs, "Eastern pancake sign" and "comedo-like structures", not previously reported to our knowledge and seen in 5 patients with alopecic and aseptic nodules of scalp (AANS). PATIENTS AND METHODS: We report on 5 patients presenting AANS. Demographic and ethnic characteristics, disease duration, clinical description, treatment and evolution were noted. Trichoscopy was performed for all patients. RESULTS: In all cases of NAAS, trichoscopy revealed 2 signs: "Eastern pancake sign" resulting in heterogeneous dilated follicular orifices without trichoscopic signs of alopecia areata, and "comedo-like structures" resembling comedones. DISCUSSION: To our knowledge, there have been no previous reports in the literature of the 2 new trichoscopic signs of AANS described herein: "Eastern pancake sign" and "comedo-like structures". The trichoscopic feature of comedo-like structures suggests the potential role of follicular occlusion in this disease. We consider that follicular occlusion may be a triggering factor in AANS.

[Pseudocyst of the scalp: two cases]. / Pseudo-kystes du cuir chevelu : deux cas.

BACKGROUND: Pseudocysts of the scalp are a poorly known entity. Herein we present two new cases. CASE REPORT: Two male patients aged respectively 42 and 33 years had been presenting a small number of pseudocystic lesions on the scalp, as well as alopecia limited to the same region, for a number of years. Inflammatory episodes had occurred in certain lesions. In one case, biopsy showed an aspect typical of pseudocyst of the scalp and the lesions appeared to stabilize on treatment with doxycycline. DISCUSSION: Pseudocysts of the scalp are also known as aseptic nodules of the scalp, a term that appears to us to be less appropriate. They form lesions involving alopecia and they may be inflammatory to various degrees. Following incision of these lesions, a deep yellow fluid liquid is released that may be shown by microbiological analysis to be sterile. Histological analysis reveals a pseudocystic wall associated with perilesional inflammatory remodelling. The cysts are frequently confused with dissecting cellulitis of the scalp, but the prognosis is more encouraging. Treatment involves surgical excision, and intralesional injections of corticosteroids or doxycycline.