Pustular eruptions in systemic disease.

M ost primary-care physicians generally equate the presence of pustules with infection. In fact, many of the conditions characterized by pustules are primary infections or are dermatoses that are secondarily infected; however, there are patients with noninfectious dermatoses that manifest with pustular lesions or with lesions that may be mistaken for cellulites. These patients often have a systemic disease or may have systemic manifestations of their dermatosis. In other articles in this issue of the journal these entities are thoroughly described. This report deals with the systemic disorders that might be associated with pustular skin lesions. Pustular diseases are characterized by a histopathologic pattern that has been called a neutrophilic vascular reaction pattern.1 This concept links together the following conditions: Behcet’s disease, rheumatoid neutrophilic dermatosis, the vesiculopustular eruption of inflammatory bowel disease, the bowel bypass syndrome, and the bowel-associated dermatitis–arthritis syndrome that occurs in inflammatory bowel disease and others with bowel surgery in whom a blind loop is created. This latter group was referred to as the “bowel-bypass syndrome without a bowel bypass.” Cutaneous lesions are part of the defining characteristics of Behcet’s disease.2 These lesions can be erythema nodosum-like, papulopustular (Fig 1), abscesses, pyoderma gangrenosum-like, palpable purpura, or lesions of Sweet’s syndrome. These lesions all demonstrate pathergy, and histopathologically they are represented by a neutrophilic vascular reaction pattern. The term “cutaneous pustular vasculitis” was coined to describe these lesions, despite the fact that they fail to demonstrate a true vasculitis.1 Elsewhere in this issue of Clinics in Dermatology, some of the systemic diseases that occur with neutrophilic dermatoses are discussed. Specifically, the article on pyoderma gangrenosum deals with arthritides, primarily rheumatoid arthritis (Fig 2) and seronegative rheumatoid-like arthritis that commonly accompany about 15% of pyoderma gangrenosum patients.3,4 Leg ulceration is common in Felty’s syndrome, a condition characterized by rheumatoid arthritis, splenomegaly, and cytopenias. These ulcerations may represent pyoderma gangrenosum or may be a “vasculitic” process.5 In addition, pyoderma gangrenosum has been observed in conjunction with psoriatic arthritis6 or spondyloarthropathies.7 One case of pyoderma gangrenosum has been reported with the SAPHO syndrome, an entity characterized by synovitis, acne, pustulosis, hyperostosis, and osteitis.8 Similarly, arthritis is a frequent feature reported with Sweet’s syndrome9–11 (Fig 3), and the article on this syndrome presents a view of the linkage. Recently we reported a patient with classic rheumatoid arthritis who at times had lesions of pyoderma gangrenosum, Sweet’s syndrome (Figs 5a and 5b), and a pustular reaction.12 She also has had a neutrophilic eye disease known as peripheral ulcerative keratitis. In addition, a case linking rheumatoid arthritis to a neutrophilic panniculitis has recently been published.13 The article by Vignon-Pennamen in this issue deals with “extracutaneous” manifestations of neutrophilic dermatoses, including arthritis. Inflammatory bowel disease was strongly linked to pyoderma gangrenosum in the 1950s,14 and even today it accounts for about 15–20% of patients.15 Both pustular vasculitis and Sweet’s syndrome, however, have been reported in conjunction with bowel disease, including blind loop syndromes.16 A vesiculopustular eruption (Fig 4) has been reported in a small number of patients with ulcerative colitis.17–19 These patients often present with fever, malaise, and a sudden onset of vesicles and pustules scattered over many body surfaces. In some of the patients, one or more of the lesions will progress to classic pyoderma gangrenosum, whereas many will heal without residua. A similar eruption reported by Jorizzo and colleagues20,21 has eventually become known as a “bowelassociated dermatosis.” After their report appeared, I recognized that one of the patients that Bechtel and I22 reported as chronic and recurrent Sweet’s syndrome (Fig 6A,B) probably had the bowel-bypass syndrome without a bowel bypass based on the presence of a blind loop created during his ulcer surgery (Billroth II). Thus, pustular eruptions may occur in patients with inflammatory bowel disease, or bowel surgery. None of those with bowel surgery have been reported to develop ulcerative lesions of pyoderma gangrenosum, but From the Division of Dermatology, University of Louisville School of Medicine, Louisville, Kentucky, USA. Address correspondence to Jeffrey P. Callen, MD, 310 East Broadway, Louisville, KY 40202, USA.