Erythema dyschromicum perstans (EDP) has similarities to lichen planus pigmentosus although the precise relationship of the two conditions has yet to be established.
How to treat it?
There is no established therapy for this condition. Having said so, there are 5 options to be considered.
1) No therapy. The condition is persistent, but may resolve over time. In a series of 4 patients followed up for 2 years in Finland, 3 showed spontaneous resolution.
2) Vitamin A. Lichen planus pigmentosus has responded (50 – 100% clearance in some patients) to vitamin A prescribed in pulses of 100,000 units daily for 15 days (pulses were repeated up to 10 times) in a study. This recommendation is considered by those who reckon that EDP is the same entity as lichen planus pigmentosus.
3) Dapsone 100 mg/day for 8 to 12 weeks might be effective (anecdotal report).
4) Oral steroids might work (anecdotal report).
5) Clofazimine* 100 mg/day for 12 weeks. It seems that clofazimine reduces the inflammatory response in EDP. 4 out of 6 patients showed marked improvement.
*Barabda L, Torres-Alvarez B, Cortes-Franco R et al. Involvement of cell adhesion and activation molecules in the pathogenesis of erythema dyschromicum perstans (ashy dermatosis): the effect of clofazimine therapy. Arch Dermatol 1997; 133: 325–9.