Telogen Effluvium After Allergic Contact Dermatitis of the Scalp

In a 6-month study conducted in 2001 at the University of Bologna, Italy, researchers observed 8 women with acute contact dermatitis of the scalp, a condition confirmed by patch testing. The study aimed to evaluate the effects of acute contact dermatitis of the scalp on the hair cycle. Increased hair loss was detected in 4 of the 7 patients who completed the study. The hair loss was mild to moderate and appeared 2 to 4 months after the episode of scalp dermatitis. A scalp biopsy from 2 patients confirmed the diagnosis of telogen effluvium, a condition characterized by temporary hair loss. The researchers concluded that allergic contact dermatitis of the scalp should be considered among the possible causes of telogen effluvium. The pathogenesis of telogen effluvium caused by contact dermatitis was unknown but was speculated to be related to cytokine release during the inflammatory process.