Management of Plantar Keratodermas_{Lessons from Pachyonychia Congenita}

Plantar keratodermas can arise due to a variety of genetically inherited mutations. The need to distinguish between different plantar keratoderma disorders is becoming increasingly apparent because there is evidence that they do not respond identically to treatment. Diagnosis can be aided by observation of other clinical manifestations, such as palmar keratoderma, more widespread hyperkeratosis of the epidermis, hair and nail dystrophies, or erythroderma. However, there are frequent cases of plantar keratoderma that occur in isolation. This review focuses on the rare autosomal dominant keratin disorder pachyonychia congenita, which presents with particularly painful plantar keratoderma for which there is no specific treatment. Typically, patients regularly trim/pare/file/grind their calluses and file/grind/clip their nails. Topical agents, including keratolytics (eg, salicylic acid, urea) and moisturizers, can provide limited benefit by softening the skin. For some patients, retinoids help to thin calluses but may lead to increased pain. This finding has stimulated a drive for alternative treatment options, from gene therapy to alternative nongenetic methods that focus on novel findings regarding the pathogenesis of pachyonychia congenita and the function of the underlying genes.