What is a fissured tongue, and can it heal?

Fissured tongue, also called scrotal tongue or lingua plicata, shows as grooves 2-6 mm deep on the top of the tongue. The most common pattern is one deep groove down the middle with smaller grooves branching off; others look like a crisscross or random cracks. DermNet notes the grooves often reach the edges and, when deep, can divide the surface into small lobes.

Cleveland Clinic estimates it affects 2-20% of people worldwide, and closer to 2-5% in the US. It is slightly more common in men and in people over 50, likely because the grooves deepen with age. Many people have had it since childhood and only notice it when they look closely.

There is no single known cause. It often runs in families, which suggests genetics play a large role. It is also seen more often alongside certain conditions, though having fissures does not mean you have any of them:

• Geographic tongue, the most frequent companion
• Psoriasis, especially pustular psoriasis
• Down syndrome
• Sjögren's syndrome
• Melkersson-Rosenthal syndrome, a rare condition with facial swelling and facial weakness, in which a fissured tongue can be the first sign
• Orofacial granulomatosis

A widely repeated claim online is that cracks in the tongue mean you are low in B vitamins. Cleveland Clinic's position is clear: a fissured tongue is not a sign that you are missing nutrients or have a vitamin deficiency.

Where the confusion comes from: deficiencies of iron, B12, folate, riboflavin and other B vitamins can cause glossitis, which makes the tongue sore, red, swollen and often smooth and shiny. A smooth sore tongue is a reason to ask a doctor about blood tests. Long-standing painless grooves on an otherwise normal-colored tongue are not. A small 1987 study of 40 people with fissured tongue syndrome found none were anemic and concluded that anemia does not play a primary role, although average B12, folate and ferritin levels were slightly lower than in controls.

The grooves themselves will not heal, and nothing needs to "fix" them. What can be treated is irritation inside them. Food and bacteria trapped in a deep groove can cause bad breath, burning or inflammation. To keep the grooves clean and calm:

1. Clean the top of your tongue once or twice a day. A scraper clears the surface coating; follow with a soft toothbrush brushed gently along the length of the main groove to lift debris from inside it.
2. Rinse with water after meals, especially after sticky or crumbly food.
3. Drink enough water through the day. A dry mouth lets debris stick in the grooves.
4. If the tongue stings, avoid spicy, acidic and very hot food until it settles, and try a toothpaste without sodium lauryl sulfate.

Most people never need treatment. If a groove becomes inflamed or infected, a dentist or doctor may treat the infection, for example with an antifungal if yeast is found. If fissures appear alongside facial swelling or facial weakness, or alongside psoriasis that is flaring, the underlying condition is managed by the relevant specialist. Diagnosis is made by looking; a biopsy is rarely needed.

Mention it at your next check-up if you are unsure what you are seeing. Book sooner if the tongue is persistently sore, red or swollen, if cleaning does not settle burning, or if you notice a single new deep crack or ulcer that is different from the rest of the pattern.