Acquired Hyperpigmentation Disorders of Uncertain Etiology

This chapter is a compilation of a few uncommon, hyperpigmented enigmatic dermatoses of unclear etiology that are difficult to diagnose and treat. They include lichen planus pigmentosus, erythema dyschromicum perstans, ashy dermatosis, idiopathic eruptive macular pigmentation, and acquired brachial cutaneous dyschromatosis. Most of them are more prevalent in Latin America or India as they usually involve patients with Fitzpatrick skin type IV and V. These dermatoses when present in dark-skinned population have a tremendous psychological impact and are often a sociocultural setback for the patients because pigmentary dermatoses are a bane of the colored population. As a result, they desperately seek treatment ranging from self-treatment with steroid-containing creams to home remedies to treatments offered by general practitioners, many of whom are not even qualified to treat. The financial impact of these treatments is significant as well as the impact on the quality of life due to the chronic nature of these diseases. Also, many of these conditions are mired in taxonomical confusion due to their similarity on several counts.