Leukotriene receptor antagonist-associated Churg–Strauss syndrome

Leukotriene Receptor Antagonist-Associated Churg–Strauss Syndrome

Leukotriene receptor antagonist-associated Churg–Strauss syndrome (LTRA-associated CSS) is a rare condition that occurs in some patients who are treated with leukotriene receptor antagonists (LTRAs) for asthma or allergic rhinitis. This syndrome is a form of Churg–Strauss syndrome (CSS), also known as eosinophilic granulomatosis with polyangiitis (EGPA), which is a type of vasculitis that affects small to medium-sized blood vessels and is characterized by eosinophilia, asthma, and allergic rhinitis.

Pathophysiology

The exact mechanism by which LTRAs may trigger CSS is not fully understood. It is hypothesized that the reduction in corticosteroid use due to the effectiveness of LTRAs in controlling asthma symptoms may unmask underlying CSS. Alternatively, LTRAs may directly contribute to the development of CSS in susceptible individuals.

Clinical Features

Patients with LTRA-associated CSS typically present with symptoms similar to those of classic CSS, including:

• Severe asthma
• Eosinophilia
• Allergic rhinitis
• Sinusitis
• Peripheral neuropathy
• Skin lesions
• Gastrointestinal involvement
• Cardiac involvement

Diagnosis

The diagnosis of LTRA-associated CSS is based on clinical criteria, laboratory findings, and histopathological evidence of vasculitis. Key diagnostic criteria include:

• History of asthma or allergic rhinitis
• Elevated eosinophil count
• Evidence of vasculitis on biopsy
• Exclusion of other causes of eosinophilia and vasculitis

Treatment

The primary treatment for LTRA-associated CSS involves discontinuing the leukotriene receptor antagonist and initiating immunosuppressive therapy. Commonly used medications include:

• Corticosteroids
• Cyclophosphamide
• Methotrexate
• Azathioprine

Prognosis

The prognosis for patients with LTRA-associated CSS varies depending on the severity of the disease and the promptness of treatment. Early diagnosis and appropriate management can lead to a favorable outcome, while delayed treatment may result in significant morbidity and mortality.

Related Pages

• Churg–Strauss syndrome
• Asthma
• Allergic rhinitis
• Vasculitis
• Eosinophilia
• Corticosteroids
• Cyclophosphamide
• Methotrexate
• Azathioprine