Unfortunately the reader hasn’t told us when she is going but she should bear in mind that the pattern of resistance to anti-malarial drugs is constantly changing and so she should check with a travel health clinic before she packs her bags.

The first precaution to take against malaria is to avoid mosquitoes. No antimalarial is 100 per cent reliable.

DEET (diethytoluamide) is the repellent of choice. I am interested in the reader’s apparent sensitivity to DEET. The occasional case of hypersensitivity, of a generalised allergy or even anaphylactic shock, to DEET have been reported, but usually the skin troubles are a local sensitivity to it rather than an allergic response. There is, therefore, sometimes a need to avoid applying it to soft skin such as is found under the arms, behind the knees, in the elbow, around the genitalia, near the eyes or lips. It may well be that if the reader avoids applying DEET to these sensitive sites all will be well.

There have been also occasional cases in which people have responded to DEET with a severe physical or even psychiatric reaction. Children are thought to be more sensitive to DEET than adults, but the extent to which this occurs is debatable.

Solutions of DEET may be of a strength of anything from 30 to 50 per cent. It needs to be applied frequently, and the stronger the solution the more effective, but the more likely it is to cause local skin irritation. Mosiguard, another repellent, is based on eucalyptus (available from most chemists). It smells better than DEET and is a natural product that is about as efficient as a 30 per cent DEET solution.

Recently an anti-insect and anti-mosquito cloth that smells rather deliciously of lavender has been marketed by Arnywear (www.arnywear.co.uk). It is claimed that it will keep insects at a distance of 50cm (about 20in) from whatever part of the body on which it is being worn. The cloth comes in various sizes that can be worn as a sarong, scarf, belt, anklet, wristband or bandana (it can also be wrapped around a pillow or neck rest). Arnywear cloth is recommended as a mosquito repellent by the London School of Medicine and Tropical Hygiene. It is also useful against insects when fishing, walking or gardening. I intend to try it against midges in the Scottish Highlands.

Mosquitoes in malarial zones should also be avoided by wearing, especially after dusk, long buttoned-up sleeves, long trousers and ankle boots. A potential danger is resting during the day in the shade, and sometimes damp, of a tree. Windows should be screened against mosquitoes.

Antimalarials are essential and are as important for those born abroad, but who have been living in England for some years, as they are for those who have never ventured further afield than Eastbourne. There is now widespread resistance to the standard anti-malarial mixture of chloroquine and paludrine. Lariam is effective but not recommended for anyone with any history of psychiatric troubles, including depression, severe reactions to so-called recreational drugs or any suggestion of neurological troubles and seizures. I recommend Malarone to my former patients and now use it myself rather than Larium.

Two musts for travellers are Travellers’ Health: How to Stay Healthy Abroad, by Dr Richard Dawood (OUP), and the pocket-sized Traveller’s Healthbook, by Jonathan Lorie and Nicholas Beeching (Wexas).

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