Diagnosis: Behçet’s disease
We diagnosed Behçet’s disease (BD) in this patient based on his clinical presentation.
BD was first described by Hulushi Behçet in 1937 as a triad of oral ulcers, genital ulcers, and uveitis.1 BD is a rare multisystem inflammatory disorder of unknown cause and is prevalent along the Silk Road, an ancient trade route from the Far East to the Mediterranean.
The prevalence is highest in Turkey (80-370/100,000 people) and <1/100,000 people in the United Kingdom and United States.2 Research suggests that the HLA-B*501 allele contributes to the risk of BD in places where the disease is prevalent, but not in Western countries.2
The development of ulceration at the site of superficial skin injury is typical of BD and is termed pathergy. Before he was referred to us, he had had multiple venipunctures while being investigated for a presumed infective illness.
Consider these conditions in the differential
The differential diagnosis includes erythema multiforme, herpes simplex, and Crohn’s disease.
Erythema multiforme is a type of hypersensitivity reaction that commonly occurs in response to infections such as herpes simplex and mycoplasma or medications such as barbiturates or penicillins. It often is diagnosed by the appearance of targetoid skin lesions.
Herpes simplex usually presents with grouped vesicles on an erythematous base and the diagnosis can be confirmed by virology; it responds to antiviral medication.
Crohn’s disease patients may develop abscesses and ulcers in the perineal/perianal region, but they will primarily complain of crampy abdominal pain, loss of appetite, weight loss, and bloody diarrhea.