Behcet’s Disease: Clinical Features, Pathogenesis, Histology and Treatment

Leonora

This online-only bonus feature is an ongoing review of past peer reveiw journal articles with significant impact on dermatology.

Behcet’s disease is a complex disease that consists of recurrent oral and general ulcerations, uveitis, synovitis, and cutaneous pustular vasculitis. In this study, 6 patients with a diagnosis of Behcet’s disease underwent complete examination including laboratory analysis, biopsy, and radiological assessment to classify the findings seen in Behcet’s disease. All 6 patients had recurrent oral and genital aphthae with negative herpes simplex virus as well as arthritis. Two patients had uveitis, and 4 patients demonstrated clinical pathergy after intradermal injection with sterile saline. No neurological issues were detected in any of the patients. Routine baseline laboratory analysis did not show any significant findings. No circulating immune complexes were detected by C1q binding assay. Biopsies of pathergy sites showed leukocytoclastic vasculitis in 1 patient, and 4 patients had “pathergy-like” histology with endothelial swelling of blood vessel walls and perivascular accumulation of polymorphonuclear cells without frank leukocytoclastic vasculitis. Heat-inactivated serum from all patients showed increased movement of polymorphonculear cells compared to controls. Among 4 patients who took dapsone for a 12-week protocol, all reported a subjective decrease in aphthae development as well as size of existing aphthae.

Reference 

Jorizzo JL, Hudson D, Schmalstieg FC, et al. Behcet’s syndrome: Immune regulation, circulating immune complexes, neutrophil migration, and colchicine therapy. J Am Acad Dermatol. 1984; 10(2): 205-214.

 

Pathergy

Pathergy, or the development of a cutaneous pustular lesion 24 hours after cutaneous trauma, is considered by many to be a clinical feature of Behcet’s disease. This study looked at the incidence of clinical pathergy among 9 patients with a diagnosis of Behcet’s. Histamine was injected intra-dermally into the arm of each patient. Clinical assessment as well as biopsy were conducted 24 hours after injection. While only 1 patient developed a pustular lesion clinically consistent with pathergy, all 9 patients showed either leukocytoclastic vasculitis or Sweet’s like vasculitis on pathological exam of the histamine injection site. These findings suggest that clinical pathergy may not be a reliable finding in Behcet’s disease, but histopathologic pathergy testing may be a useful adjunct.

Reference 

Jorizzo JL, Solomon AR, Cavallo T. Behcet’s syndrome: Immunopathologic and histopathologic assessment of pathergy lesions is useful in diagnosis and follow-up. Arch Pathol Lab Med. 1985;109(8): 747-751. 

 

Treating with Thalidomide

While thalidomide is used off-label for several dermatologic conditions, its use is restricted by the risk of teratogenicity and peripheral neuropathy. Its mechanism of action has not been elucidated, but is believed to modulated circulating immune complex mediated damage and neutrophil-mediated cytotoxicity. This study looked at the effect of oral thalidomide in patients with Behcet’s disease or bowel-associated dermatosis-arthritis. Five patients took thalidomide 200 mg daily for 4 weeks “on” and 4 weeks “off” cycles for a total study period of 12 weeks. No subjective side effects, including peripheral neuropathy, were reported. Hematological and chemistry assessments were all normal. Peripheral nerve conduction studies were unchanged during thalidomide study period. One patient stopped the study prematurely after developing a macular eruption thought to be from thalidomide. Another patient stopped after a major thermal burn, unrelated to the study. Two patients demonstrated complete resolution of their oral and genital aphthae as well as improved arthritis symptoms, and another patient had 75% improvement of aphthae and symptoms. This study was one of the first to demonstrate efficacy of thalidomide for Behcet’s disease.

Reference

Jorizzo JL, Schmalstieg FC, Solomon AR, et al. Thalidomide effects in Behcet’s syndrome and pustular vasculitis. Arch Intern Med. 1986;146(5): 878-881