Itchy skin is a common complaint. Sometimes it is caused by something as simple as dry skin or an insect bite and settles within a short time. In other cases, persistent itching may be a sign of a skin condition, an allergic reaction or an underlying health problem.
The medical term for itching is pruritus. It can affect a small area of the body or occur all over the skin. Some people may also develop redness, rashes, bumps, dryness or peeling, while others may experience severe itching without any obvious change on the skin.
Finding the cause is important because scratching alone may provide temporary relief while making the skin more irritated or increasing the risk of infection.
In this article, Tribune Online highlights 10 common causes of itchy skin you should know.
Dry skin
Dry skin is one of the simplest and most common causes of itching. When the skin loses too much moisture, it can become rough, tight, flaky and irritated. The itching may be worse during periods of dry weather or after taking long, hot baths.
Frequent washing, harsh soaps and some skincare products can also strip the skin of its natural oils. Using a gentle, fragrance-free moisturiser regularly, particularly after bathing, can help restore moisture and reduce irritation.
Eczema
Eczema refers to a group of conditions that cause the skin to become dry, itchy and inflamed. Atopic dermatitis is a common form. It may cause patches of dry, red or darker-looking skin, depending on a person’s skin tone. Scratching can make the affected areas sore and may cause the skin to thicken over time.
Eczema can flare up in response to different triggers, including certain soaps, fabrics, heat, sweating, stress and allergens. People with frequent or severe flare-ups may need treatment prescribed by a healthcare professional.
Allergic reactions
An allergic reaction can cause sudden itching, often accompanied by a rash or raised patches known as hives. Possible triggers include certain foods, medicines, insect bites, cosmetics, soaps, detergents and other substances.
Hives may appear and disappear within hours, with new areas becoming affected as others settle. A mild allergic rash may resolve after the trigger is avoided, but medical advice may be needed if the reaction keeps returning.
If itching or hives occur together with swelling of the lips, tongue or throat, difficulty breathing, dizziness or fainting, emergency medical care is needed because these can be signs of a severe allergic reaction.
Insect bites
Mosquitoes, bedbugs, fleas and other insects can cause localised itching after biting the skin.
The affected area may become red, swollen or develop a small raised bump. In some people, the reaction may be more noticeable and last for several days.
Avoiding scratching is important because broken skin can become infected. If several household members develop itchy bites, particularly after sleeping, it may be worth checking bedding, mattresses and other areas where insects may be hiding.
Scabies
Scabies is caused by tiny mites that burrow into the upper layer of the skin. It usually causes intense itching, which is often worse at night. Small bumps or a rash may appear, particularly between the fingers, around the wrists, waist, armpits and other areas where the mites commonly affect the skin.
Because scabies can spread through close skin-to-skin contact, more than one person in a household may become affected. Treatment usually involves specific medicines designed to kill the mites. People should not rely on ordinary anti-itch creams alone if scabies is suspected.
Fungal skin infections
Fungal infections can cause itching, scaling and changes in the appearance of the skin.
Ringworm is one example. Despite its name, it is caused by a fungus rather than a worm. It can produce a circular or ring-shaped rash that may gradually spread.
Fungal infections can affect different parts of the body, including the groin, feet and scalp.
Keeping affected areas clean and dry can help, but appropriate antifungal treatment may be necessary. Using steroid creams on a fungal infection without medical advice can sometimes make the infection worse or harder to recognise.
Contact dermatitis
Sometimes the skin becomes itchy and inflamed after coming into contact with a substance that irritates it or triggers an allergic reaction. This is known as contact dermatitis.
Common triggers include soaps, detergents, perfumes, cosmetics, hair products, cleaning chemicals and some metals.
The rash usually develops in the area that came into contact with the substance. It may cause redness, itching, swelling, dryness or small blisters. Identifying and avoiding the trigger is an important part of managing contact dermatitis.
Liver or kidney problems
Persistent itching without an obvious skin rash can sometimes be associated with problems affecting internal organs. Certain liver diseases can cause itching because substances normally processed or excreted by the liver build up in the body.
Advanced kidney disease can also cause widespread itching, particularly when the kidneys are no longer effectively removing waste products from the blood. This does not mean that unexplained itching automatically indicates liver or kidney disease. There are many possible causes.
However, widespread or persistent itching without a clear skin problem, particularly when accompanied by other symptoms such as yellowing of the eyes or skin, swelling, changes in urination or unusual tiredness, should be medically assessed.
Medicines
Some medicines can cause itching as a side effect or trigger an allergic reaction. The reaction may occur shortly after starting a medicine, although not every drug-related skin reaction happens immediately. Medicines can sometimes cause itching with or without a visible rash.
Anyone who develops widespread itching, hives or swelling after starting a new medicine should contact a healthcare professional for advice. If there is difficulty breathing, swelling of the face or throat, severe dizziness or fainting, emergency treatment is required.
People should not stop essential prescription medicines without discussing the problem with a doctor or pharmacist, unless they are experiencing a severe allergic reaction and have been instructed to seek emergency care.
10. Other underlying health conditions
Persistent itching can sometimes occur alongside other medical conditions. Thyroid disorders, diabetes, certain blood disorders and some neurological conditions can cause or contribute to itching in some people. In rare cases, widespread unexplained itching can occur with certain cancers, particularly some blood cancers.
Again, itching alone does not mean that a person has one of these diseases. Most cases have more common explanations. The important point is that unexplained itching that persists, keeps returning or is accompanied by other unusual symptoms should not simply be ignored.