Blau syndrome following a bacterial infection

Area of Science:

• Pediatric Rheumatology
• Genetics
• Ophthalmology

Background:

• Blau syndrome is a rare, early-onset autoinflammatory disease characterized by dermatitis, arthritis, and uveitis.
• It is caused by mutations in the NOD2 gene, which plays a role in immune system regulation.
• Early diagnosis and management are crucial to prevent long-term complications.

Observation:

• An 11-month-old female infant presented with a severe triad of dermatitis, boggy arthritis, and keratitis.
• These symptoms emerged shortly after hospitalization for bacterial pneumonia.
• Despite escalating immune-modulating therapies, her condition, including ocular findings, progressed.

Findings:

• Skin biopsy and genetic testing confirmed Blau syndrome, linked to a pathogenic NOD2 variant.
• The patient developed bilateral panuveitis, optic disk edema, and hypopigmented chorioretinitis.
• The clinical course suggests a potential trigger or exacerbation by the preceding bacterial infection.

Implications:

• This case underscores the potential for bacterial infections to precipitate or worsen inflammatory responses in individuals with genetic predisposition, such as NOD2 variants.
• It highlights the diagnostic challenges and aggressive nature of Blau syndrome, even with advanced therapies.
• Further research into the interplay between infection and autoinflammation in Blau syndrome is warranted.