Dr Rosemary Leonard

GETTING TO THE HEART OF MEDICAL MATTERS

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Q I got a couple of nasty insect bites last week and the skin around them became red and swollen. I went to a walk-in centre and was told to take antihistamines. The swelling is gradually going down but shouldn't I have been given antibiotics?

A Insect bites and stings contain chemicals that can irritate the skin, and lead to the release of histamine, which in turns causes redness, swelling and itching, often within half an hour.

The size of this reaction can vary hugely between individuals. In some, there is only a very small red area, but in others there can be a far larger reaction, with swelling several inches across. For a few people, a bite or sting can lead to a more generalised, serious allergic reaction, which can be life threatening.

Infections from stings are not very common, and though the initial signs of this are similar to a local reaction - redness and swelling - they do not appear for at least 24 hours, often longer, and the skin often feels sore and tender, rather than itchy.

Other signs that a bite is infected is yellow pus developing in the bite site, or feeling unwell, with a fever, and if this happens, you should seek medical advice as soon as possible.

You can help reduce the chance of a localised reaction to a bite or sting by keeping the skin clean and applying a cold flannel or ice pack. If swelling does start, you can take an antihistamine tablet, like cetirizine or loratadine, which is more effective than applying antihistamine cream.