A single typical trichoscopic feature is predictive of tinea capitis: a prospective multicentre study.

BACKGROUND: Specific trichoscopic signs of tinea capitis (TC) were first described in 2008. The accuracy of this diagnostic tool has not been evaluated. OBJECTIVES: To assess the diagnostic accuracy of trichoscopy. METHODS: A prospective, multicentre study was done between March 2015 and March 2017 at the dermatology departments of four French university medical centres. Patients with a presumed diagnosis of TC were included. Trichoscopy was considered to be positive if at least one specific trichoscopic sign was observed. Trichoscopy results were compared with the gold standard for diagnosis of TC (mycological culture). RESULTS: One hundred patients were included. Culture was positive for 53 patients and negative for 47. The sensitivity of trichoscopy was 94% [95% confidence interval (CI) 88-100], specificity was 83% (95% CI 72-94), positive predictive value was 92% and negative predictive value was 86%. Comma hairs, corkscrew hairs, zigzag hairs, Morse-code-like hairs and whitish sheath were significantly more frequent in patients with a positive mycological culture (P < 0·001). Comma hairs were more frequent in patients with Trichophyton TC (P = 0·026), and zigzag hairs were more frequent in patients with Microsporum TC (P < 0·001). Morse-code-like hair was not observed in any patients with Trichophyton TC and therefore appears to be highly specific for Microsporum TC. CONCLUSIONS: The presence of a single trichoscopic finding is predictive of TC. Trichoscopy is a useful, rapid, painless, highly sensitive tool for the diagnosis of TC - even for dermoscopists with little experience of trichoscopy. It enhances physicians' ability to make treatment decisions. What's already known about this topic? Tinea capitis (TC) must be confirmed by a mycological culture that may take up to 6 weeks, delaying treatment. Specific trichoscopic signs of TC were first described in 2008, but the accuracy of trichoscopy for diagnosing TC has not previously been evaluated. What does this study add? The present series is the largest yet on the use of trichoscopy in the diagnosis of TC. Our results demonstrated that the presence of a single feature (comma hair, corkscrew hair, zigzag hair, Morse-code-like hair or whitish sheath) is predictive of TC. Trichoscopy is painless and highly sensitive. Morse-code-like hair appears to be highly specific for Microsporum TC.

[Actinomycosis revealed by ulceration of the palate and gingiva]. / Actinomycose révélée par une ulcération du palais et de la gencive.

BACKGROUND: Actinomycosis is a chronic and extensive granulomatous, bacterial infection. Revelation by oral ulceration is rare. PATIENTS AND METHODS: A 76-year-old patient with diabetes was treated with dabrafenib for stage IV melanoma. A follow-up visit revealed two ulcerated, infiltrated and hyperalgesic lesions of the palate and gingiva. There were no associated signs. The laboratory findings were normal. The possibility of squamous cell carcinoma occurring with BRAF inhibitors was discussed, despite the rarity of such cases in the literature. Histological examination showed an actinomycotic grain. A scan of the facial mass showed no osteitis. Antimicrobial therapy was initiated with amoxicillin for four months, with a favorable outcome. DISCUSSION: Actinomycetes are Gram-positive filamentous saprophytic bacteria of the oral cavity and the gastrointestinal tract. They can become pathogenic under the influence of several factors. Cervicofacial involvement in the form of a peri-mandibular inflammatory nodule with secondary fistulation on the skin or in the mouth is the classic presentation. To our knowledge, no cases of opportunistic infection under BRAF inhibitors have been described. Only two cases of tuberculosis have been reported with sorafenib. The initial presentation led to suspicion of squamous cell carcinoma. In our patient, poor oral hygiene and diabetes were the two key factors considered. Moreover, this is the first case reported under dabrafenib, which does not appear to be a favoring factor. We would stress the importance of mucosal examination in patients treated with BRAF inhibitors.