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Snapshot diagnosis - what's causing the black spots on this woman's tongue?

Dr Mike Wyndham shares a case in which black spots on a woman’s tongue made her suspect she had a virus

Dr Mike Wyndham shares a case in which black spots on a woman's tongue made her suspect she had a virus

The patient

The 32-year-old woman had been feeling perfectly well until she poked her tongue out in fun at a close friend who was teasing her. The observant friend noted some ‘black spots' on her tongue and wondered whether it could be a virus as her roses had been struck down with something looking very similar! The patient had little relevant medical history apart from the fact that she was an occasional smoker.

First instinct

Her friend was correct that roses do get black spot, but this woman's problem certainly wasn't viral. Viral conditions tend to cause ulcers in the mouth. The pigmentation was mostly confined to the tongue but there was a little on the lips too. I wondered whether this might be Peutz-Jeghers syndrome.

Differential diagnosis

• Peutz-Jeghers syndrome

• amalgam tattoo from drilling or spread through dental extraction

• melanosis from smoking

• drug-induced pigmentation (anti-malarials, amiodarone, minocycline, cyclophosphamide).

Getting on the right track

Inspection of the teeth showed excellent dentition with no amalgam fillings. She was only an occasional smoker, making this an unlikely cause. There was no history of abdominal pain nor family history of bowel disease suggestive of Peutz-Jeghers, which has an autosomal dominant inheritance.


A check on the drug history gave the answer. She was taking minocycline for acne and this was the undoubted cause of the pigmentation. The drug was stopped and fortunately the pigmentation disappeared.

Dr Mike Wyndham is a GP in Edgware, north London

What is causing this black pigmentation? What is causing this black pigmentation?

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