Idiopathic Guttate Hypomelanosis (IGH)

• Epidemiology: affects men and women of all ethnic backgrounds
• Etiology: sunlight could be a factor but genetic factory (family history) play a more important role
• Clinically: lesions are typically located on the shins and then on the arms
• Histology: melanocytes morphologically intact but melanization is suppressed (synthesis of melanin). Epidermis may be slightly atrophic
• Treatment: pimecrolimus (cacineurin inhibitors) and cryotherapy have been tried but often yield unsatisfactory results.

Contributors:

Dr Christophe HSU – dermatologist. Geneva, Switzerland

Source of information: Nordlund J. Disorders of Pigmentation. 70th Annual Meeting of the AAD (American Academy of Dermatology) – San Diego, California, United States of America (USA)