Maximal Points of Head's Zone in Fixed Drug Eruption.

The principles determining the primary localization of lesions in fixed drug eruption (FDE) are still unknown. Studies investigating the predilection areas in FDE have indicated drug-related, trauma-related, or inflammation-related specific site involvement, as well as visceracutaneous reflex-related specific site involvement. The importance of viscerocutaneous reflexes for the location of dermatoses was first recognized in the 1960s. Head's zones are viscerocutaneous reflex projection fields on the skin that extend over certain dermatomes and possess a reflex-associated maximal point. Recently, in a Turkish collective of patients, three women with the primary location of FDE lesions on the maximal points of Head's zones were presented. We also experienced 3 cases with FDE where the lesions were located at specific sites (buttocks), the so-called maximal points of Head's zones, which are known to be the most active dermatomal areas of an underlying visceral pathology. An underlying internal disturbance (ureter stone, pyelonephritis and chronic pelvic inflammatory disease) was found in all 3 patients, corresponding to the organ-related maximal point of Head's zones in each case. In conclusion, the primary location of FDE lesions on the maximal points of Head's zones revealed relevant organ disorders with corresponding projection fields.