Occasionally, BHT may be caused by the use of antimicrobial medications (e.g., tetracyclines), or oxidizing mouthwashes or antacids. A soft diet may be involved as normally food has an abrasive action on the tongue, which keeps the filiform papillae short. Pellagra, a condition caused by niacin (vitamin B3) deficiency, may cause a thick greyish fur to develop on the dorsal tongue, along with other oral signs.Transient surface discoloration of the tongue and other soft tissues in the mouth can occur in the absence of hairy tongue. Causes include smoking (or betel chewing), some foods and beverages (e.g., coffee, tea or liquorice), and certain medications (e.g., chlorhexidine, iron salts, or bismuth subsalicylate (Pepto-Bismol)). Diagnosis
Diagnosis is usually made on the clinical appearance without the need for a tissue biopsy. However, when biopsies have been taken, the histologic appearance is one of marked elongation and hyperparakeratosis of the filiform papillae and numerous bacteria growing on the epithelial surface.Hairy tongue may be confused with hairy leukoplakia, however the latter usually occurs on the sides of the tongue and is associated with an opportunistic infection with Epstein–Barr virus on a background immunocompromise (almost always human immunodeficiency virus infection but rarely other conditions which suppress the immune system). Classification
Hairy tongue (lingua villosa) refers to a marked accumulation of keratin on the filiform papillae on the dorsal surface of the tongue, giving a hair-like appearance. Black tongue (lingua nigra) refers to a black discoloration of the tongue, which may or may not be associated with hairy tongue.
There is currently uncertainty about the effectiveness of anaesthesia or analgesia for manual extraction, in terms of pain and the risk of postpartum haemorrhage. Very rarely a curettage is necessary to ensure that no remnants of the placenta remain (in rare conditions with very adherent placenta such as a placenta accreta). However, in birth centers and attended home birth environments, it is common for licensed care providers to wait for the placentas birth up to 2 hours in some instances. Other animals
Retention of fetal membranes (afterbirth) is observed more frequently in cattle than in other animals. In a normal condition, a cow’s placenta is expelled within a 12-hour period after calving. == References ==