Itch is the uncomfortable, irritating feeling which creates the desire to scratch. It can be the result of a nearly endless number of possible causes, ranging from skin conditions, such as eczema or poison oak, to internal diseases.
Itch can occur with no visible skin changes or may be marked by redness, raised spots or bumps, blisters, cracked or dry skin, or scaly skin texture.
Unfortunately, scratching itchy skin often makes the itch worse, which can set off an itch-scratch cycle.
The only way to get lasting relief from itch is to identify and treat the underlying cause. Most cases of itch can be treated easily with medications, cold compresses, cool baths, or light-based therapy.
What conditions are associated with itch and itching?
Dry skin is the most common culprit for causing itch in skin that has no obvious signs of rash or other changes. Dry skin can result from hot or cold temperatures, indoor heating and cooling systems, or washing or bathing excessively.
These conditions may also cause itchy skin:
- Skin conditions and rashes, such as scabies, lice, chickenpox, hives, psoriasis, eczema (dermatitis).
- Internal disorders, such as celiac disease, liver problems, kidney failure, anemia, certain cancers, and thyroid dysfunction. These conditions may produce itch over the entire body with no outward changes in the skin (except for the scratched areas).
- Irritants and allergens, including cleaning products, soaps, wool, poison ivy or cosmetics. Wool, chemicals, soaps and other substances can irritate the skin and cause itching.
- Food allergies
- Certain medications, like antibiotics or antifungals, can provoke rashes in some people.
When should I seek medical advice for itch?
If your itch lasts more than a couple weeks, is severe enough to disrupt your everyday activities or sleep, has no obvious cause, or affects your whole body, see a doctor or dermatologist. You should also see a doctor if the itch occurs with other symptoms, such as fatigue, weight loss, bowel or urinary problems, fever, or skin redness.
How will my doctor test and diagnose my itch?
Your doctor will likely start by giving you a physical exam and getting your health history, including when the itching started, what makes it worse or improves it, what cosmetics and skin care products you use, and what you do to care for your skin.
If an underlying condition is suspected, your doctor may run diagnostic tests, such as a blood test.
After the exam and any diagnostic tests, it may be determined that your itching is a symptom of one of the following related conditions:
- Dermatitis (eczema). Dermatitis causes swelling, irritation, itchiness, and redness and can be caused by many factors, including contact irritants or allergens (such as nickel or wool).
- Psoriasis. In this disorder, the accelerated lifecycle of skin cells causes rough, dry patches on the skin from accumulated dead skin cells. These patches are called scales and often look thick and silvery, and are sometimes painful.
- Fungal infections. The tinea fungus is a common culprit in itchy skin, being the root cause of athlete’s foot, ringworm, and jock itch.
- Hives. These itchy, raised bumps are often caused by allergies to certain foods or medications.
- Lice. The intense itching of body lice or head lice is hard to ignore. A lice infestation is easily spread and often identifiable by the small, red bumps caused by the tiny, wingless parasites.
- Scabies. Scabies are tiny mites that burrow into the skin, causing intense itching wherever they are present. This condition is contagious.
What are the complications of prolonged itch?
Unfortunately, itching is often intensified when scratched, which can lead to complications like neurodermatitis, a condition that causes the skin to become red, raw, thick and leathery. These patches can become infected and lead to scarring or pigment changes in the skin.
What are the treatments for itch?
Depending on the cause of your itch, the treatment may include:
- Medications, including topical corticosteroid creams or oral antihistamines
- Wet dressings, in which you apply medicated cream to the itchy areas and cover them with moist cotton material—the dampness of the dressing helps the skin absorb the medication.
- Treating any underlying disease. If your doctor has identified an underlying disease that’s causing the itch, then he or she will treat that disease, possibly combining that treatment with those listed above.
- Light therapy (phototherapy). This involves exposing the affected areas to certain wavelengths of ultraviolet (UV) light in multiple sessions until the itch is resolved.
For more immediate relief, you may want to try certain topical medications, such as creams, ointments, and lotions containing lidocaine, benzocaine, menthol, camphor, or calamine. However, these solutions should only be used in the short term until the primary cause of the itch has been resolved.