Systemic lupus erythematosus, rheumatoid arthritis, Crohn's disease, Wegener's granulomatosis, and other autoimmune disease can manifest with disease in the larynx. The throat manifestations of autoimmune disease are variable, but can include chronic redness, swelling, and ulceration of the vocal cords (chronic laryngitis), "bamboo" nodules (mid-vocal cord swelling), and in the case of Wegener's granulomatosis narrowing below the vocal cords (subglottic stenosis). In general disease will improve and worsen along with systemic disease. Because autoimmune disease can be controlled rather than cured relapse of vocal cord disease is not uncommon.
When prolonged laryngitis exists without explanation, it is useful to consider autoimmune disease and proceed with the appropriate blood tests and consider referral to a rheumatologist.