Pachyonychia congenita, a paradigm for rare skin disorders

Pachyonychia congenita: pathogenesis of pain and approaches to treatment

Pachyonychia congenita (PC) is an autosomal dominant genodermatosis characterized by a triad of chronic severe plantar pain, focal palmoplantar keratoderma and hypertrophic nail dystrophy. Plantar pain can be debilitating and have a profound impact on quality of life. Current therapeutic options for pain in PC are limited to lifestyle adjustment and mechanical techniques, with a small subgroup of patients benefiting from oral retinoids. This review investigates the pathogenesis of pain in PC and provides a summary of the current and future therapeutic options.

ALA-iPDT for follicular occlusion tetrad concomitant with pachyonychia congenital type Ⅱ and ankylosing spondylitis

The follicular occlusion tetrad is a complex dermatologic syndrome which can concomitant with other diseases. The case reported a young male patient suffer from follicular occlusion tetrad (acne conglobata, hidradenitis suppurativa, dissecting cellulitis of the scalp, and pilonidal sinuses) concomitant with pachyonychia congenital type Ⅱ (thickened nails, palmoplantar keratoderma, multiple cysts) and ankylosing spondylitis (lumbago, human leukocyte antigen-B27 positive). The genetic analysis showed the KRT17 gene mutation on exon 1 (c.T284C) supports the diagnosis. Whereupon, a comprehensive therapy scheme of 5-aminolevulinic acid-mediated interstitial photodynamic therapy (ALA-iPDT) combined surgery and drug is tried and worked. This case reports a rare condition and propose a therapeutic option that may work.