Implications of a clinically ignored site of acanthosis nigricans: the knuckles.

BACKGROUND: The clinical epidemiology of acanthosis nigricans (AN) has not been entirely studied. Most studies mention only its prevalence taking any "typical site" as a whole. These studies were carried out at different ages, races, anthropometries, and skin phototypes without analyzing the comparative clinical connotation of different sites. Furthermore, it has never been explored as a potential early expression of insulin resistance before it becomes clinically evident. The objective was to determine the prevalence and body distribution of AN in easy-access sites to physical examination in a Latin American youth population and its clinical implications as an early marker for obesity. DESIGN AND PATIENTS: We conducted a prospective, cross-sectional, observational study in 703 randomly selected students. Participants' mean age was 19.1±1.68 years. Overweight and obesity occurred in 23.6% and 6.8%, respectively. 3 observers blindly assessed neck, axillae, elbow and knuckles. RESULTS: AN was identified in any of the examined sites in 47.8% of the participants. Its prevalence increased from 41% to 86% from normal to obese anthropometric categories. AN occurred in 1-4 sites in 23.1%, 10.8%, 6.9% and 7.1% of cases, respectively. The knuckles was the site with the highest prevalence of AN as an overall group (31.3%) and in the normal (24.9%) and overweight body mass index (46.4%) categories and there was a higher prevalence in the cases above the median in the normal body mass index category. In the obese group, AN was slightly more common in the neck but all sites had a very similar high prevalence. CONCLUSION: AN occurs with a high prevalence in Latin American youths, and its prevalence is much higher in a "non-classical" and ignored location where it is very easy to detect during physical examination: the knuckles. It may also occur earlier in this location in the evolution to obesity. The presence of AN in the knuckles in any patient, even if they have a normal body mass index, might indicate the likelihood of an early clinical manifestation of insulin resistance and metabolic consequences.

Combination therapy with adapalene-benzoyl peroxide and oral lymecycline in the treatment of moderate to severe acne vulgaris: a multicentre, randomized, double-blind controlled study.

BACKGROUND: Oral antibiotics in association with a topical retinoid with or without benzoyl peroxide (BPO) are the recommended first-line option in the treatment of moderate to severe acne vulgaris. OBJECTIVES: To evaluate the efficacy and safety of oral lymecycline 300 mg with adapalene 0·1%-BPO 2·5% (A/BPO) fixed-dose gel in comparison with oral lymecycline 300 mg with a vehicle gel in subjects with moderate to severe acne vulgaris. METHODS: A total of 378 subjects were randomized in a double-blind, controlled trial to receive once-daily lymecycline with either A/BPO or vehicle for 12 weeks. Evaluations included percentage changes from baseline in lesion counts, success rate (subjects 'clear' or 'almost clear'), skin tolerability, adverse events and patients' satisfaction. RESULTS: The median percentage reduction from baseline in total lesion counts at week 12 was significantly higher (P < 0·001) in the lymecycline with A/BPO group (-74·1%) than in the lymecycline with vehicle group (-56·8%). The success rate was significantly higher (47·6% vs. 33·7%, P = 0·002) in subjects treated with lymecycline and A/BPO. Both inflammatory and noninflammatory lesions were significantly reduced at week 12 (both P < 0·001) with a rapid onset of action from week 2 for noninflammatory lesions (P < 0·001) and week 4 for inflammatory lesions (P = 0·005). The A/BPO and lymecycline combination was well tolerated. The proportion of satisfied and very satisfied subjects was similar in both groups, but the number in the A/BPO group who were 'very satisfied' was significantly greater (P = 0·031). CONCLUSION: These results demonstrate the clinical benefit of combining A/BPO with lymecycline in the treatment of moderate to severe acne vulgaris.

Sabinas syndrome in monozygotic twins.

A pair of 2-year-old female monozygotic twins presented with short and brittle hair. There was marked reduction in hair density, and excessive curving of the eyelashes. Onychodystrophy was also evident. They also had developmental delay in verbal and motor skills. Neither their parents nor other relatives were known to be affected, and there was no history of consanguinity. Examination of the hair shaft under light microscopy showed trichoschisis, which was more evident under electron microscopy. Under polarized light, the hair shafts showed the pathognomonic 'tiger-tail' pattern. The level of sulphur in the hair was low. Both patients were negative for TTDN1 mutation. Clinical correlation was performed and the diagnosis of Sabinas syndrome was made. Sabinas syndrome is a very rare autosomal recessive disorder first described in a group of patients from a small community in north-eastern Mexico. It is diagnosable at birth, and its major symptoms include brittle hair, mental retardation and nail dysplasia. Structural hair abnormalities are seen by both light and electron microscopy.