Acrodermatitis continua is a rare chronic localized pustular and scaly inflammation which is classified as a form of acropustular psoriasis, characterized by sterile, pustular eruptions that initially affect the tips of fingers or less often on the toes12. Nail destruction can be possible and in late stage it can affect bones resulting in atrophy of the distal phalanx1234. It has been known to have chronic course with localized lesion on the digits12. Spontaneous improvement have rarely been observed and in some cases, outbreaks of generalized eruptions on the entire body can occur15.

A 51-year-old female visited psoriasis clinic of National Medical Center in December, 2013. She had a long history of pustular psoriasis limited on the fingers and palms for 14 years that eruptively spread to the trunk and extremities for 3 weeks. Patient has been diagnosed with localized pustular psoriasis on the phalanges and palms of both hands at the age of 37. Her compliance with the treatment was not good, nevertheless she never showed psoriasis lesion other than hands.

A review of systems revealed that the patient had mild febrile sensation and generalized myalgia and on physical examination, the patient presented with hyperkeratotic scaly patches with desquamation on the palms and fingers and dystrophic finger nails with deformed finger tips (Fig. 1A). Multiple tiny pustules on erythematous skin could be seen on the trunk and extremities (Fig. 1B, C). Image study showed irregular bony absorption on distal phalangeal tuft (Fig. 2). After 3 weeks of acitretin 20 mg/day, the patient showed minimal residual psoriatic lesions on the trunk and extremities and pustules was not detectable.

Acrodermatitis continua typically occurs after minor trauma or infection at or near the tip of a single digit, more often a finger than a toe12. Localized inflammation persists and pustules develop and desiccate into psoriasiform scaling1. Initial lesion is at the tip of the digit, but soon the nail folds and nail bed may be involved and the nail plate becomes dystrophic12. In most cases it tends to remain localized to the digits for months or years and but it extends slowly to the proximal12.

Pustulation of the nail bed and nail matrix almost always occurs and may lead to severe onychodystrophy or even to anonychia which eventually cause inflammation and sclerosis of the underlying soft tissue12. Osteitis of phalanges resulting in osteolysis and involvement of interphalangeal joints can occur in longstanding cases.

Acrodermatitis continua rarely but may evolve in to generalized form especially in the elderly. According to our knowledge, there have been very few case reports in the past about acrodermatitis continua evolving into generalized pustular psoriasis as in our case.

In summary, we present a case of acrodermatitis continua which, after many years, was followed by osteolysis and atrophy of the distal phalanx that eventually evoluted into generalized pustular psoriasis.