Chronic laryngitis is a condition characterized by laryngeal inflammation lasting for longer than six weeks. It leads to waxing and waning dysphonia and hoarseness of voice and may be a precursor to laryngeal cancer. Vocal abuse, smoking, laryngopharyngeal reflux, and allergies are some of the causes of chronic laryngitis.
Chronic laryngitis (CL) is chronic laryngeal inflammation with an annual incidence of about 4 cases per population of 1000 [1]. The most common cause of CL is laryngopharyngeal reflux but other causes include vocal abuse (singing, teaching), smoking, excessive alcohol and caffeine intake, bacterial and fungal infections as well as occupations like glass blowing [2] [3] [4].
Patients usually present with waxing and waning dysphonia, globus (foreign body) sensation in the throat, pain in the throat, constant urge to clear the throat, and dry cough. Symptoms of dysphonia include reduced volume, hoarseness, raw sensation, inability to modulate the voice and vocal fatigue.The symptoms depend on the severity of the inflammation. In severe infections, patients may have a fever, laryngeal edema, dyspnea and even stridor. Chronic laryngeal mucosal injury secondary to gastroduodenal reflux (GERD) of acidic contents has been implicated as a cause of CL in almost 50% of the patients [5]. Clinical features of CL associated with GERD are called laryngopharyngeal reflux (LPR) as the main region affected is the laryngopharynx [6] [7].
The diagnosis of CL is based on clinical evaluation and patient history. It is vital for the otolaryngologist to inquire about the patient's occupation, allergies, vocal abuse and infections (tuberculosis). During the physical examination, an indirect, as well as, flexible nasopharyngolaryngoscopy is performed in all patients presenting with dysphonia lasting longer than 3 weeks. LPR can be diagnosed on the basis of the presenting symptoms and the appearance of laryngeal edema and arytenoid erythema on laryngoscopy [8]. In addition, thick, sticky mucus may be noticed in the piriform sinuses and valleculae. A video-stroboscopy provides information about vocal fold anatomy, vibratory pattern and can help to differentiate between a sulcus vocalis from mucosal stiffness. If infective etiology is suspected then a complete blood cell count, erythrocyte sedimentation rate with sputum cultures and sensitivities for bacteria, fungi, and viruses should be ordered. Serology for autoimmune disorders like sarcoidosis should also be considered. Skin allergy testing is recommended if an allergic etiology is suspected. Barium swallow, manometry and 24 hour pH monitoring are recommended for the diagnosis of GERD.
Although plain X-ray neck has no role in the diagnosis of CL, plain X-ray chest may help to detect pulmonary tuberculosis or sarcoidosis as the cause of CL. Computed tomographic scan and magnetic resonance scan are not routinely performed but may help to detect soft tissue changes, structural laryngeal changes, as well as, tumors.
Microlaryngoscopy under general anesthesia to visualize the larynx with a microscope may be necessary to detect tiny lesions and obtain tissue for biopsy, as well as for staining and cultures. The histological examination may reveal pachydermia (in long-term smoker's CL), amyloidosis, granulomatous lesions as well as malignancies. Lipoid proteinosis with hyaline deposits can mimic chronic laryngitis [9] on histology.