bites in pairs

A couple weeks ago I woke up with 2 hives on my lower back.  I would not have noticed them if I had not accidentally ran my finger over them.  They only then became itchy.  About a week later, I noticed 2 more hives on my lower thigh and then 2 more a week later on my ankle.  They seem to come in twos and are about an inch a part.  I checked for bed bugs and found no sign of them.  As well, the only bites I got while in bed were the first 2.  Any ideas?

[Paderla Anitha, DNB]

Hello and hope you are doing well.

Hives develop in response to an allergic reaction, by the release of histamine. The allergen can be medications, food, extremes of temperature, exercise and viral infections to name a few.

Normally, during the course of evolution from a baby to an adult, we develop a mechanism by which we desensitize ourselves to all the materials we are exposed to. But sometimes, the desensitization may not be perfect and we develop allergic reactions to those few substances. This is what happened in your case. On exposure to the allergen, an Immunologic (IgE) or a non-immunologic reaction is set in process, which ultimately releases histamine, which acts at the peripheral receptors, resulting in allergic reactions and rashes.

The aim of the therapy is identification and removal of trigger factor. It is the most important and the only effective long-term therapy. It may help to maintain a food dairy and keep monitoring your symptoms. This will help to narrow the search and avoid them. Environmental triggers or seasonal or diurnal variations triggers may be difficult to avoid. But being aware can help to avoid the same. Just keep monitoring for other sources of allergens.

Local measures like ice packs and antipruritic lotions are helpful. Antihistamines block the histamine receptors and prevent histamine from acting and thus help in preventing rashes.

Hope this helped and do keep us posted.