Orbital myositis following streptococcal pharyngitis in a pediatric patient

Orbital myositis is a relatively rare ocular inflammatory disease. It is currently classified as an idiopathic orbital inflammatory disease, but has been associated with ocular and systemic disorders, including scleritis, rheumatoid arthritis, Crohn's disease, and systemic lupus erythematosis. Orbital myositis has also been associated with infectious disease such as streptococcal pharyngitis, viral upper respiratory infection, and Borrelia burgdorferi infection.

This report documents treatment and imaging of a 13-year-old boy who had an episode of right-sided orbital myositis following streptococcal pharyngitis with anti-streptolysin-o (ASO) titer elevation to 1,188 IU/ml. Clinically, this patient demonstrated acute onset of marked restriction and mild under-action of the lateral rectus muscle of the right eye. Thickening of the lateral and medial recti was demonstrated on computed tomography. The mild orbital myositis was treated with oral nonsteroidal anti-inflammatory drug therapy. The nonconcomitant strabismus resolved approximately 7 weeks after initial presentation. General orbital inflammatory disease management and the association of upper respiratory tract infection with orbital myositis are discussed.

Orbital myositis is a distinct clinical entity that can occur after streptococcal upper respiratory infection, consisting of pain on ocular movement, localized swelling, restrictive strabismus, and inflammatory signs of the involved muscle(s).