Subcorneal pustular dermatosis accompanied by seronegative arthritis.

Abstract

Sir, 870–1,700), IgA 420mg/dl (normal range, 110–410), IgM 297 mg/dl (normal range, 46–260). On the basis of Subcorneal pustular dermatosis (SPD) is a rare disorder characterized by a chronic benign and relapsing a diagnosis of SPD, the patient was treated with 75mg dapsone, daily. Skin lesions and arthralgia responded vesicopustular eruption that generally aVects the trunk, particularly at  exural sites (1). Despite marked promptly to dapsone, and resolved completely within 5 days. At present the patient’s condition is good, with improvements in investigative techniques, the pathogenesis is still controversial. In some patients, SPD has been few skin lesions and very little arthralgia under daily treatment with 25mg dapsone. described in association with monoclonal gammopathies (2) and multiple myeloma (3). Furthermore, in addition to other neutrophilic dermatoses (Sweet’s syndrome, DISCUSSION pyoderma gangrenosum and erythema elevatum diutinum), SPD has been reported to be associated with In the literature 5 cases of SPD with seropositive arthritis in ammatory diseases such as rheumatoid arthritis (RA) have been reported and 3 cases of SPD with seronegative (4) and Crohn’s disease (5). Here we describe a patient arthritis (4, 6). However, as Butt & Burge (4) pointed with a long history of SPD with arthritis that was nonout, the diagnosis is uncertain in 3 of these cases: one typical RA. We found only one report in the literature patient with seropositive arthritis who died after develsimilar to our case. SPD accompanied by seronegative oping a generalized pustular rash may have had pustular arthritis is extremely rare. psoriasis; the clinical features in 2 cases with seronegative arthritis, which occurred in reaction to infection and settled in 2 weeks, suggest pustular bacteroid (7, 8). CASE REPORT Thus, we suggest that this is the second fully conŽ rmed report of SPD accompanied by seronegative arthritis. A 33-year-old woman presented with a 20-year history of skin eruption and joint manifestation. When she was The other fully conŽ rmed case (9) was similar to our case regarding the following points: 1) onset was in 13 years old, she developed a symmetrical rash beginning on the extensor surface of both knees. Skin lesions childhood; 2) eruptions and arthralgia began at almost the same time; 3) skin lesions and arthralgia responded increased in number and were disseminated over almost her entire body, except for her head. Joint manifestations promptly and were resolved by treatment with dapsone. Based on the laboratory data, radiographic Ž ndings with occasional swelling and dull pain began in elbows, knees, wrists and Ž ngers, almost at the same time as the and clinical course, the arthritis in our case was nontypical RA. We speculated that seronegative arthritis occurrence of the skin lesions. Thereafter, the skin lesions and joint manifestations repeatedly appeared and may have been caused mainly by aseptic inŽ ltration of neutrophils into the joints as well as into the epidermis, disappeared. On examination,  accid pustules and vesicles were present on her trunk and extremities. since the arthralgia promptly disappeared after treatment with dapsone. On the other hand, in cases of SPD Nikolsky’s sign was negative. There were no mucosal lesions. Examination of the joints revealed mild tenaccompanied by seropositive arthritis, arthritis generally precedes skin eruptions (4, 10). Thus, the immune derness and swelling of some joints including elbows, knees, wrists and hands. In particular, swelling and conditions in RA may contribute to the onset of SPD. Concerning the response of arthritis to dapsone treattenderness of the right third proximal and distal interphalangeal joint were marked. ment in the literature, some cases responded (10), but others did not (4). Since dapsone is not a standard Skin biopsy histology showed subcorneal pustules composed of neutrophils, without acantholysis. A direct medicine for RA, it seems reasonable that seropositive arthritis should not respond to dapsone and the reason immuno uorescence study was negative. Bacterial cultures of swabs from skin were also negative. The Ž ndings that some seropositive arthritis responded to dapsone has still to be investigated. One explanation could be were consistent with SPD, but not with IgA pemphigus. A full blood count and biochemical screening that dapsone diminishes the additive symptoms of arthritis due to aseptic inŽ ltration of neutrophils as well were within the normal ranges. Rheumatoid factor, antinuclear antibody and anti-DNA antibody were negaas seronegative arthritis, but not the symptoms of RA itself. tive. Serum IgG level was 2,520mg/dl (normal range,