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 > or = 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.