Many people find the worst symptom of their eczema is severe itching.Scratching relieves the itch, but also makes the inflammation and the itching worse because it causes more inflammatory substances to be released within the skin.Sedating antihistamines cause drowsiness and may therefore affect your ability to drive or operate machinery safely.This should not be a problem if you take them before going to bed, but be aware of your potentially reduced ability if you are going to perform any hazardous tasks.In addition, if you have liver or kidney disease you may need a lower dose of these medicines, though this depends on the particular medicine prescribed.
Often you will find that the itchiness of your skin is reduced when you use regular moisturisers to keep the skin soothed and hydrated, and control the inflammation with topical corticosteroids or other newer medicines.
The released histamine binds to its receptors (H-1 receptors) causing a chain reaction that includes an increase in blood flow to the area, and the release of other chemicals that add to the allergic response. Antihistamines work by blocking histamine receptors, therefore reducing the reactions that cause itching.
However, histamine is only one of many substances in the body that cause itching, and these medicines are mainly of value in eczema because they cause sedation.
All medicines have possible side-effects, though you may not necessarily experience any.
Side-effects from antihistamines are more likely to occur in children and the elderly, and some of the most common ones associated with this type of medicine are listed below.
More information about the potential side-effects associated with each specific medicine can be found in the patient information leaflet that will be provided with the medicine.