False-positive tuberculin test in Behçet's syndrome

Area of Science:

• Immunology
• Dermatology
• Ophthalmology

Background:

• Behçet's syndrome is a rare multisystem inflammatory disorder.
• Characteristic symptoms include oral ulcers, genital ulcers, skin lesions, and eye inflammation.
• The syndrome's presentation can be variable and sometimes mimics other conditions.

Observation:

• The patient presented with uveitis and erythema nodosum, indicative of Behçet's syndrome.
• Every needle puncture on the patient's skin resulted in a pustule formation.
• A tuberculin skin test was strongly positive due to the pustule reaction at the puncture site.

Findings:

• The positive tuberculin test was a direct result of the pathergy phenomenon in Behçet's syndrome, not tuberculosis.
• The patient eventually developed the full spectrum of Behçet's disease symptoms.
• This case underscores the diagnostic challenge posed by the pathergy phenomenon.

Implications:

• Misinterpretation of the tuberculin test could lead to incorrect diagnosis and treatment.
• Awareness of the pathergy phenomenon is crucial for accurate diagnosis of Behçet's syndrome.
• Early recognition of atypical presentations can prevent diagnostic delays and improve patient outcomes.