Acrodermatitis Continua of Hallopeau Evolving into Generalised Pustular Psoriasis

Abstract

Sir, We report a case of a 21-year-old male who presented to our outpatient department with asymptomatic pustules in the tips of fingers alone for last 3 years with no preceding history of psoriasis lesions. Ten days back, patient developed generalized pustular eruption all over the body with high-grade fever. There was no evidence of focal sepsis, hypocalcemia, irritant application, or steroid intake prior to this eruption. He had no arthritis and no family history of psoriasis. He received acitretin (50 mg/day) and methotrexate (10 mg/week) for acrodermatitis continua for 4 months continuously from a private practitioner with no response. He stopped these drugs just prior to the generalized pustular eruption. On physical examination, he had generalized bilaterally symmetrical involvement with sheets of erythema covered by pustules forming dried-up lakes of pus [Figure 1]. All the finger nails were completely obscured by deep-seated pustules with severe erythema and scaling of adjacent proximal nail fold extending up to the proximal interphalangeal joint [Figure 2]. Only the second toe nails showed acrodermatitis lesions. He had atypical acral involvement with complete anonychia of all the involved nails and tapering of the fingers. Figure 1 Sheets of erythema with dried-up lakes of pus and scaling seen over the trunk Figure 2 Finger nails obscured by dried-up pustules with inflammation of nail fold and proximal interphalangeal joints On admission, he developed crops of postulation with fever spikes of 103°F every 2 days. Gram's stain of the pus revealed only neutrophils. Pus culture was sterile. Hemogram was normal, except for neutrophilic leukocytosis. Serum electrolytes, serum calcium, liver and renal function tests were found to be within normal limits. X-ray skiagram of the hands and feet were found to be normal with no evidence of osteolysis or psoriatic arthritis. Skin biopsy from the back showed hyperkeratosis, parakeratosis with subcorneal collection of neutrophils, consistent with pustular psoriasis. On the basis of the above clinical and histopathological findings, we made a diagnosis of acrodermatitis continua of Hallopeau evolving into generalized pustular psoriasis. Treatment was initiated with cyclosporine 100 mg twice-daily (5 mg/kg/day). Two days later, patient was symptomatically better with subjective and objective improvement. Six days after the start of cyclosporine, pustules cleared all over the body, except for a few plaques over the extensor aspect of both arms and forearms, which showed local recurrence of pustules. Nail bed pustules also cleared partially, and nail fold plaques resolved completely. All the biochemical parameters remained within normal limits during follow-up. Cyclosporine was maintained at the same dose for a month and then slowly tapered. Generalized pustular psoriasis showed optimal response to therapy, whereas acrodermatitis continua of hallopeau was partially responsive to this treatment, [Figure 3] hence potent topical steroids (halobetasol propionate 0.05%) was added. Figure 3 Finger nail beds showing few pustules with anonychia of all the nails after 2 weeks of treatment There have been very few reports in the past of acrodermatitis continua of Hallopeau evolving into GPP. There has been only 1 report from London in 1968 of 8 cases of acral pustular psoriasis in middle-aged females, which evolved into GPP in 1 to 2 years' time.[1] They also were not able to identify any precipitating factors in their cases. However, in our case, evolution into GPP could be due to sudden withdrawal of acitretin and methotrexate. GPP is usually preceded by past history of psoriasis vulgaris, but psoriasis negative GPP has been reported once from China among 12 children of juvenile GPP with no past or family history of psoriasis.[2] Our patient had adult onset acrodermatitis continua of Hallopeau evolving into GPP with no past or family history of psoriasis vulgaris. Acrodermatitis continua of Hallopeau is usually refractory to all forms of topical and systemic therapies, sometimes requiring biologicals for disease control.[3 4] There has been one case report of remission of acrodermatitis continua of Hallopeau with low-dose cyclosporine (5 mg/kg/day) but, they required high potent topical steroids with 3.3 mg/kg/day of cyclosporine for maintenance.[5] Some reports have shown effectiveness of high-dose cyclosporine in acrodermatitis continua of Hallopeau (6 and 14 mg/kg/day).[6 7] Our patient was started on cyclosporine at dose of 5 mg/kg/day, and he showed more than 90% clearance of GPP in 1 week' time, and complete remission of acrodermatitis was achieved with combination of systemic cyclosporine and topical steroids within 4 weeks.