Itchy skin (pruritus) is an uncomfortable, irritating sensation that can make scratching irresistible. It seems simple enough – when you itch, you scratch.

But itchy skin can have hundreds of possible causes, ranging from skin conditions, such as eczema or poison oak, to internal diseases. Unfortunately, scratching itchy skin often makes the itch worse, which can set off an itch-scratch cycle.

Q: What conditions are associated with itch and itching?

A: 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, sun exposure, or washing or bathing excessively.

These conditions may also cause itchy skin:

• Skin conditions and rashes, such as scabies, lice, chickenpox, hives, psoriasis, eczema.

• 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.

• Pregnancy

Q: When should I seek medical advice for an itch?

A: 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 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

Q: What are the treatments for itching?

A: 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 immediate relief, you might want to try certain topical medications, such as anti-itch creams. However, if your itch persists, call a dermatologist and schedule a consult.

Dr. Oswald Lightsey Mikell, certified by the American Board of Dermatology and the American Board of Cosmetic Surgery, is the owner of Dermatology Associates of the Lowcountry.