Itching, or itchy skin (the medical name is pruritus), is a common symptom of a wide range of conditions. It may occur in one area of the body (localised) or all over (generalised). There may be a rash or spot where the itching occurs.
Common causes of itching
Itching can be caused by allergic reactions, skin conditions, insect bites, infections, or conditions that affect the body as a whole. Generalised pruritus without a rash (especially in people over the age of 65) is usually caused by dry skin. Sometimes it is not possible to determine the exact cause of the itch.
Allergies and other reactions
- Substances that cause the immune system to react in a way that affects the skin and may cause itching are called allergens. Some people may be allergic to ingredients in cosmetics and toiletries, or in detergents. Certain metals, such as nickel or cobalt in jewellery, or rubber (in latex gloves, for example), or the dyes in some textiles can cause an allergic skin reaction. Some plants and flowers may cause skin irritation, including daffodils, tulips, chrysanthemums and primulas.
- Itching of the skin can be caused by an allergy to certain foods, or types of medication (for example, aspirin and a group of medicines called opioids).
- Prickly heat caused by strong sunlight can cause itching.
- Eczema, where the skin is dry, red and flaky.
- Psoriasis, a skin condition that causes red, flaky, crusty patches of skin covered with silvery scales.
- Lichen planus, a non-infectious, itchy rash that can affect many parts of the body. The cause is unknown.
- Urticaria, also known as nettle rash, hives, or welts, is triggered by an allergen, and causes a raised, red itchy rash on the skin.
- Contact dermatitis, an inflammation of the skin that occurs after contact with an irritant (a substance that directly damages the outer layer of the skin) or an allergen.
- Inflammation of the hair follicles ( folliculitis).
- Prurigo, a skin condition causing small blisters which are very itchy.
Insects and parasites
- Fungal infections, such as athlete’s foot which can cause itching between the toes, and ‘jock’ itch which can cause itching around the groin. Ringworm causes a ring-like red rash on the skin and scalp that can be itchy.
- Yeast infections, such as vaginal thrush or thrush in men, can cause itching in and around the genitals.
- Chickenpox or other viral infections.