Atopic Dermatitis as a Potential Portal of Septic Arthritis

Objective: Skin lesions of atopic dermatitis are highly colonized with gram-positive bacteria, which may enter the blood stream through the broken skin barrier. This paper described the association between atopic dermatitis and septic arthritis in an attempt to emphasize the importance of a high index of clinical suspicion for the correct diagnosis of bacterial arthritis in patients with atopic dermatitis. Methods: We reported one and two infections of sacroiliac joint and knees, respectively, in patients with atopic dermatitis. A systematic search of the literature revealed one case of septic arthritis of hip joint in association with atopic dermatitis. We discussed the clinical features and treatment of the articular infections. Results: In combination with localized pain, elevation of white blood cells, erythrocyte sedimentation rate, and Creactive protein indicated hematogenous articular infection in the patients at the age of 13-27 with poorly controlled atopic dermatitis. Magnetic resonance imaging was useful to identify deep articular infections. Staphylococcus aureus was the predominant pathogen, while group A streptococcus was less frequently isolated. For confirmation of the causative bacteria and spectrum of antibiotic sensitivities, skin culture was helpful in case of negative identification of the pathogen from culture of synovial fluid. Treatment with antibiotics against Staphylococcus aureus and group A streptococcus with or without surgical management resulted in good outcome. Conclusion: This case series was the first report suggesting the association between septic arthritis and atopic dermatitis. Patients with poorly controlled atopic dermatitis may be at high risk of septic arthritis because the broken skin barrier could become a potential portal of pathogens.