Itching or pruritis can be frustrating, especially if you don't know what's causing it.
There are many causes and types of itchy skin. The sensation might be localized to a specific area or experienced all over the body. If itching is related to a rash or bite, it is easy to determine where it is coming from, but sometimes, pruritus causes aren't obvious, which is when things can get complicated.
Many insect bites can itch, including those from mosquitos, sandflies, fleas, fire ants, bed bugs, lice, flies, chiggers, and scabies. Most insect bites resolve on their own in a day or two, and you can care for them at home. Applying a cold, damp cloth to the bite can reduce swelling, and calamine lotion, baking soda paste, or hydrocortisone cream can soothe itching.
The main thing to look out for is anaphylaxis. Some people have severe allergic reactions to insect bites. If you experience difficulty breathing, swelling of the face or throat, hives, dizziness, or fainting after an insect bite, seek emergency medical attention.
Contact dermatitis occurs after the skin comes into contact with an irritant or allergen. The reaction does not always happen immediately and may not appear for up to 48 hours after exposure.
Many things can cause contact dermatitis, but some of the most common are soaps, detergents, perfumes, latex, fragrances, and plants like poison ivy, poison oak, or poison sumac. In addition to itching, symptoms include redness, swelling, blistering, and thick, scaly skin.
Itching is also a symptom of heat rash. Heat rash is more common in babies and children, but it can affect adults, too, especially in hot and humid climates.
Heat rash develops when sweat gets trapped against the skin. In infants, it usually develops on the chest, shoulders, and neck; in adults, it typically appears in skin folds and where clothing rubs against the skin. Heat rash can appear as small blisters or deeper red lumps; some types are very itchy.
Anyone can get hives, but they are more common in people with asthma and allergies. These raised red splotches or welts result from an allergic reaction.
Some hives are incredibly itchy, but they can also burn or sting. They vary significantly in size, ranging from as small as a pencil eraser to as large as a dinner plate. Most hives fade in 24 hours or so, but they may last for several days.
Atopic dermatitis or eczema is a condition that damages the skin's barrier layer, making it more sensitive. Eczema is more common in people with a history of asthma and allergies.
Infants are prone to getting eczema, but most outgrow it. Teens and adults with eczema get dry, bumpy, and itchy skin that can appear anywhere but is most common on the neck, hands, inner elbows, ankles, and feet. Eczema has no cure, and treatment aims at preventing flares and reducing discomfort.
Multiple fungal infections cause itching, including ringworm. Ringworm is an itchy red circular rash with a clear patch in the middle that typically appears on the trunk, arms, or legs. It is contagious and can spread from person to person or animal to person. You can also get ringworm from touching an object that an infected person or animal has come in contact with or from infected soil.
Ringworm is related to jock itch and athlete's foot, which also cause localized itchy rashes.
Itching is a side effect of many medications. Antifungals can cause an itchy red rash, and opioid pain medications can cause generalized itching.
Itching from antibiotics is a common sign that the person may be allergic to the medication and is more common with certain classes, like sulfa-based antibiotics and vancomycin.
The brain plays an essential role in the perception of itch, so much so that the symptom sometimes originates in the brain. Psychogenic itching is a disorder where the brain plays a role in triggering the itch or the intensity or persistence of the itch, and research shows it seems to be associated with depression or anxiety.
This phenomenon is poorly studied, but doctors believe it can be classified as a somatoform disorder, which is one where the patient has physical symptoms that a physical cause cannot explain.
Unexplained chronic itching can also result from an underlying neurological disease. A variety of conditions can lead to neuropathic itch, including stroke, peripheral nerve damage, shingles, spinal cord lesions, cranial nerve damage, and phantom pain in amputated body parts.
Treatment of neurogenic itching can be complex. Common options include Botox injections, pain medications, antiseizure medications, neurostimulation, and wrapping the affected area to prevent scratching injuries.
Sometimes, itching is a sign of a systemic condition. People with advanced kidney and liver diseases often experience generalized itching, as do those with endocrine disorders like hyperthyroidism, hypothyroidism, diabetes, Cushing syndrome, Addison's disease, and polycystic ovarian syndrome.
Anemia can cause itching, as can more severe conditions like cancer and HIV. Some people with chronic heart failure also experience itching.
This site offers information designed for educational purposes only. You should not rely on any information on this site as a substitute for professional medical advice, diagnosis, treatment, or as a substitute for, professional counseling care, advice, diagnosis, or treatment. If you have any concerns or questions about your health, you should always consult with a physician or other healthcare professional.