Erythema nodosum in Singapore.

A retrospective study was carried out of all patients presenting with erythema nodosum over a 3-year period (1994-1997) at the National Skin Centre, Singapore. There were 75 patients, aged 4-70 years with a peak (40%) in the 21-30-year-old age group; 65 were female and 10 were male, giving a female to male ratio of 6.5 : 1. Precipitating factors included viral respiratory tract infections and streptococcal pharyngitis in 20 cases (26%), tuberculosis in two cases (3%), pregnancy in three cases (4%) and miscellaneous conditions: Behcet's syndrome (two cases), gonorrhoea (one case), varicella (one case) and cat-scratch disease (one case). The cause was unknown in 45 cases (60%). The pattern of erythema nodosum in Singapore is similar to that reported in the Western literature except that sarcoidosis and inflammatory bowel disease are uncommon associations.