Overlap between maculopapular exanthema and DRESS among cutaneous adverse drug reactions in a dermatology ward (2008-2012)

Results We analyzed 132 patients (85F/47M; mean age of 63.98 ±17.68 years) with maculopapular exanthema (MPE) (21.2%), DRESS (28.0%), overlap MP/DR (25.8%), Stevens-Johnson syndrome/toxic epidermal necrolysis (12.1%), acute generalized exanthematous pustulosis (8.3%), fixed drug eruption (3.78%) and urticaria/angioedema (0.76%), caused mainly by allopurinol (36.5%), antimicrobials (30.8%) and anticonvulsants (14.4%). MPE occurred in 28 patients, 21F/7M, mean age of 68±19,71 years; DRESS in 37 patients, 25F/12M, mean age of 61,38±18,07 years, and MP/DR in 34 patients, 13M/21F, mean age of 64.06 ± 17.06 years, with no significant difference between sex or age. In MP/DR, generalized exanthema was associated with face involvement in 73.5% vs 89.2% in DRESS. Liver was affected in 61.8% vs 78.4% in DRESS, with mild cytolysis in 90.5% (median highest ALT value 109 IU/L, Interquartile range (IQR) 75-162) and mild cholestasis in 61.9% (medium highest GGT 196 IU/L, IQR 87-337), values usually inferior to DRESS (median ALT 131 (IQR 92-392) and GGT 211 (IQR 110-519). Eosinophilia occurred in 11.8% of MP/DR vs 78.4% in DRESS, with an average relative eosinophilia of 18.8%±12% vs 16%±7% in DRESS. Allopurinol was the most frequent culprit drug both in MP/DR (38.5%) and DRESS (51.1%), antibiotics were the culprit in 47.5% of MPE, 26.9% of MP/DR and 20.7% of DRESS. Latency period in MP/DR (18.06 ± 13.17 days) was significantly longer than in MPE (11.04 ± 9.33), however shorter than DRESS (23.85 ± 13,80).