Hairy tongue is due to hyperplasia and elongation of the filiform papillae, which form hair-like overgrowths on the dorsum. The filaments can be several millimeters long. The color varies from pale brown to intense black. The discoloration is due to proliferation of chromogenic bacteria and fungi.
Hairy tongue is usually seen in older individuals, and smoking, antiseptic mouthwashes, antibiotics and diets lacking abrasive foodstuffs are the most common predisposing factors.
The dorsum of the tongue may also become blackened without elongation of the filiform papillae by antibiotic mouthwashes such as tetracycline and iron compounds. Hairy tongue is rarely biopsied. Microscopically, it is characterized by irregular, hyperplastic filiform papillae showing hyperorthokeratosis or hyperparakeratois with numerous bacterial conglomerates and filamentous organisms in the surface layers and more deeply between fronds of epithelium.
It has been shown by immunocytochemical analysis of keratin expression that in black hairy tongue there is defective desquamation of cells in the central column of the filiform papillae. This results in the typical highly elongated, cornified spines that are the characteristic feature of the condition.
Etiology of hairy tongue
The etiology is unknown. However, factors that may be associated with hairy tongue include emotional stress, smoking, poor oral hygiene, oxidizing mouthwashes, radiation, systemic antibiotics, in particular, metro-diazole, and Candida albicans.
Pathogenesis of hairy tongue
- Normally the keratinized surface layers of the tongue papillae are continuously desquamated through friction of the tongue with food, the rough surface of the palate and the upper anterior teeth. Following desquamation, tongue papillae are replaced by newer epithelial cells from below.
- Lack of tongue movements due to local or systematic diseases disturbs the regular desquamation process of the tongue papillae, especially the filiform papillae, which lengthens and produces a hairy appearance on the tongue surface.
- Such hypertrophied papillae are often coated with microorganisms and become discolored by retaining pigments from foods, medicines and chromogenic bacteria, etc.
Clinical Features of hairy tongue
- Hairy tongue commonly affects the mid dorsum of the tongue.
- Hypertrophy of the filiform papilla produces a thick matted layer on the dorsal surface.
- Hairy tongue in extreme cases may produce a thick, leathery coating on the tongue surface and this condition is often known as earthy or encrusted tongue.
- Hypertrophied filiform papilla often brushes soft palate and produce gagging sensations.
- Hairy tongue cases may produce halitosis.
- There can be irritation to the tongue due to accumulation of food debris and micro-organisms.
- Hairy tongue is often considered as the mirror of general health status since it is often associated with various systemic diseases.
Differential diagnosis: – This condition has to be differentiated from Candidiasis, leukoplakia, oral lichen planus and oral hairy leukoplakia. Culture of the tongue’s dorsal surface may be taken if a superimposed oral Candidiasis or other specific oral infection is suspected. Distinguishing between oral hairy leukoplakia and hairy tongue is important if patients are found or suspected to be HIV positive. This can be accomplished by a simple mucosal punch biopsy and appropriate immune staining of the specimen for the presence of Epstein-Barr virus, the causative agent of oral hairy leukoplakia.
However, in most cases, the diagnosis is made retrospectively on the basis of the clinical responses to mechanical debridement.
Diagnosis of hairy tongue
The diagnosis can usually be made on the basis of appearance and history. As indicated above, HT can appear grossly discolored, depending upon chromogens from bacteria, foods, drugs, and mouth rinses, and a variety of products with oral mucosal , such as combustible and smokeless tobacco, lozenges and wines.
These substances are absorbed by the thickened keratin covering the elongated papillae causing the transient staining.
A biopsy is elective. Histopathology shows elongated hair- like projections of keratinized surface epithelial cells, some interspersed debris and microbial flora, and a moderate inflammatory infiltrate. Whereas Candidal overgrowth can be found in some cases, it is usually a result, and not the cause of Hairy tongue .
Treatment of hairy tongue
- Stop any predisposing etiologic factor.
- High level of oral hygiene.
- Patients should be reassured that the condition is benign.
- Recurrences are common.
- In mid cases, brushing the dorsum of the tongue with a tongue cleaner every morning for 1 month or more any improvement the condition.
- In severe cases, with very long filiform papillae, topical application of keratolytic agents such as 30-50% trichloroacetic acid or salicylic acid in alcohol or 40% urea in water destroys the elongated papillae and restores the tongue to normal. Trichloroacetic acid is the best and should be applied with care once. It can be reapplied in 1 week’s time if there are remnants of the elongated papillae.
- Topical or systemic antifungal do not have place in the treatment of hairy tongue.
Homeopathic treatment of hairy tongue – Homeopathy is one of the most popular holistic systems of medicine. The selection of remedy is based upon the theory of individualization and symptoms similarity by using holistic approach. This is the only way through which a state of complete health can be regained by removing all the sign and symptoms from which the patient is suffering. The aim of homeopathy is not only to treat hairy tongue but to address its underlying cause and individual susceptibility. As far as therapeutic medication is concerned, several remedies are available to cure hairy tongue symptoms that can be selected on the basis of cause, sensations and modalities of the complaints. For individualized remedy selection and treatment, the patient should consult a qualified homeopathic doctor in person. There are following remedies which are helpful in the treatment of hairy tongue:
Nux Mos, Silicea, Kali Brom, Sticta, Mezereum, Kali Bi, Lycopodium, Natrum Mur, Phosphorus, Natrum Phos, Merc Sol.
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George Laskaris- Treatment of oral diseases: concise textbook; 2004; 81
Purkait- Essential of Oral Pathology; 2005; 20
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Sol Silverman,Lewis R. Eversole, Edmond L. Turelove- Essential of oral medicine ; 2002 ; 253