Objective:

To present a case of an 18-month-old girl with MEF2C haploinsufficiency syndrome who developed concurrent Kawasaki disease and Stevens-Johnson syndrome.

Approach:

• Case Presentation: An 18-month-old girl presented with fever, rash, facial swelling, and oliguria after recent immunizations. Initial treatment for presumed Streptococcal pharyngitis was ineffective, leading to hospitalization.
• Diagnostic Evaluation: Upon admission, she exhibited signs of Kawasaki disease-associated shock and was treated with IVIG and anakinra. Laboratory tests indicated coagulopathy and hepatic dysfunction.
• Clinical Progression: Despite initial treatment, she developed symptoms consistent with Stevens-Johnson syndrome, including skin desquamation and bullae formation, prompting a reevaluation of her diagnosis.

Key Findings:

• The patient exhibited symptoms of Kawasaki disease including fever, rash, and hypotension.
• Laboratory tests showed neutrophil predominant leukocytosis, acute kidney injury, and coagulopathy.
• Skin biopsy suggested an interface drug eruption or evolving Stevens-Johnson syndrome.

Interpretation:

This case illustrates the diagnostic challenges of concurrent Kawasaki disease and Stevens-Johnson syndrome in a pediatric patient with MEF2C haploinsufficiency syndrome.

Limitations:

• The patient's previous genetic testing documentation was unavailable.
• The diagnosis was complicated by the overlapping symptoms of Kawasaki disease and Stevens-Johnson syndrome.

Conclusion:

This case highlights the complexities in managing pediatric patients with concurrent inflammatory conditions.