Blau Syndrome With Delayed Cutaneous Manifestations: A Case Report

Area of Science:

• Genetics
• Immunology
• Dermatology

Background:

• Blau syndrome is a rare autoinflammatory disorder with autosomal dominant inheritance.
• It presents with granulomatous dermatitis, polyarthritis, and uveitis, often misdiagnosed as juvenile idiopathic arthritis.
• Gain-of-function mutations in nucleotide-binding oligomerization domain 2 (NOD2) are implicated in Blau syndrome pathogenesis.

Observation:

• A 37-year-old male with a history of juvenile idiopathic arthritis and uveitis developed asymptomatic pink papules.
• Histopathological examination revealed noncaseating dermal granulomas with Langerhans-type giant cells.

Findings:

• Genetic testing confirmed a NOD2 mutation in the patient.
• The clinical presentation, histology, and genetic findings led to a diagnosis of Blau syndrome.

Implications:

• This case underscores the importance of considering Blau syndrome in patients with chronic inflammatory conditions, even with atypical presentations.
• Accurate diagnosis through genetic testing is crucial for appropriate management and understanding of autoinflammatory diseases.
• Recognizing Blau syndrome can prevent misdiagnosis and delayed treatment for patients with NOD2-associated autoinflammation.