Clinical features and associated morbidity of scabies in a rural community in Alagoas, Brazil

OBJECTIVE To describe the clinical characteristics of scabies and the associated morbidity in an impoverished rural community in northeast Brazil. METHOD A door-to-door survey was made to examine twice the population of an endemic area; first at the end of the rainy season, and a second time in the dry season 4 months later. RESULTS In total, 2005 individuals were examined. The overall prevalence of scabies was 9.8% (95% CI 8.5-11.2). Predilection sites with similar relative frequencies in all age groups were the abdomen (83.7%) and the inguinal area/inner part of the thighs (66.3%). Hands, feet, genitals and the scalp/neck/face were significantly more often affected in children < 7 years (all P < 0.03). Fifty-five per cent of the patients showed scabies lesions simultaneously at >= 12 distinct topographic areas. Papular lesions were most commonly found, followed by papular-crusted lesions. Vesicles were significantly more often observed in children (P = 0.04). Sixty-four per cent of the patients had three or more types of lesions. Local lymphadenopathy was present in 53.6% and superinfection in 36.7% of the cases. The number of topographic areas affected, as well as the proportion of superinfected lesions, was inversely correlated with age (rho = -0.22, P = 0.002 and rho = -0.358, P < 0.05, respectively). The quantity of skin surface infested, the proportion of superinfected lesions and the presence of a superinfected lesion distal to an enlarged lymphnode were predictors of lymphadenopathy. Seventy-two per cent of the patients suffered from sleep disorders, mainly because of itching. CONCLUSION Scabies is associated with considerable morbidity in this endemic community. Predilection sites, clinical presentation, quantity of skin surface affected and proportion of secondary infected lesions show a dichotomy between children and adults.