QI have a strawberry birthmark that covers most of my left leg. Even though I am comfortable with this mark, I have heard that it’s now possible to have it removed. Can this be done on the NHS and if not, what is the cost? Is the treatment painful and would it leave scars?

CJ from Leigh-on-Sea

AThese birthmarks are also known as strawberry naevi or infantile haemangiomas. Their cause remains poorly understood but they are thought to be a harmless overgrowth of blood vessels in the skin.

Pulsed-dye laser treatment can help here and is available at specialist centres in the UK — sometimes on the NHS. You should see a dermatologist to get an exact diagnosis first, though, as your options depend on the type of mark that you have. The treatment is not painful as an anaesthetic cream is used on the area and it usually leaves only minimal scarring. Visit www.birthmarksupportgroup.org.uk for detailed advice.

QI will be trekking to Everest base camp in 2009. What can I do to avoid altitude sickness? If I do get it, are there drugs I can take to address the symptoms?

PM from London

AAltitude sickness — also known as acute mountain sickness or AMS — happens in almost half of all people travelling on foot above 14,000ft. It can be triggered by the lower air pressure at higher altitudes. Other triggers include making a rapid ascent to high altitude and performing hard physical exertion while there.

Symptoms typically occur 6-36 hours after arriving at high altitudes and include headache, fatigue, vomiting and shortness of breath.

Medication such as acetazolamide and dexamethasone can treat AMS symptoms, but the only cure is either acclimatisation or descent. For more on AMS go to www.altitude.org .

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