Antipruritic

Antipruritics, also known as anti-itch drugs, are medications that inhibit the itching (Latin: pruritus) often associated with sunburns, allergic reactions, eczema, psoriasis, chickenpox, fungal infections, insect bites and stings like those from mosquitoes, fleas, and mites, and contact dermatitis and urticaria caused by plants such as poison ivy (urushiol-induced contact dermatitis) or stinging nettle.

Common antipruritics

Topical antipruritics in the form of creams and sprays are often available over the counter. Oral anti-itch drugs also exist and are usually prescription drugs. The active ingredients usually belong to these classes:

• Antihistamines such as diphenhydramine (Benadryl) and Hydroxyzine
• Corticosteroids such as hydrocortisone topical cream, see topical steroid
• Counterirritants, such as mint oil, menthol, or camphor^[1]
• Local anesthetics such as lidocaine, pramoxine, or benzocaine in topical creams or lotions
• Nalfurafine, an orally-administered, centrally-acting κ-opioid receptor agonist approved for uremic pruritus and effective in animal models of other prurituses^[2]

Disputed and questionable antipruritics

• Burow's solution, an astringent aqueous solution of aluminium acetate, is shown to soothe and to relieve itching.
• Olive oil
• Jewelweed has been shown to be devoid of any anti-itch activity in several controlled studies ^[3][4][5][6]
• Selective serotonin reuptake inhibitor are a class of medicines commonly used for depression, and are also said to be effective in controlling pruritus in a small number of refractory cases.^[7] Mirtazapine, a different type of antidepressant, also has antipruritic effects due to its strong antagonism of the H₁ receptor.
• Calamine lotion, containing zinc oxide and iron(III) oxide, is a traditional remedy for mild itching, such as that typically associated with chicken pox – although the U.S. Food and Drug Administration has asserted that it has little if any scientific evidence.^[8][9] Nevertheless, they subsequently recommended applying topical OTC skin protectants, such as calamine, to relieve the itch caused by poisonous plants such as poison ivy, poison oak, and poison sumac.^[10]
• Paste of sodium bicarbonate (baking soda) and water, applied topically^[11]
• Ammonium hydroxide (household ammonia), applied topically^[11]
• Papain-based topical creams.

Home remedies

• Cooling with ice or cold water (usually stops the itch for as long as the ice or cold water is applied)
• Slightly painful stimulation such as rubbing, slapping, scratching, or heating based on a spinal antagonism between pain- and itch-processing neurons
• Pine tree gum applied to the affected areas for short periods of time can help in drawing out the oils and drying the skin.
• Frequent washing of the affected areas in hot water with a drying soap removes oils that come to the surface as the blisters form and provides temporary relief from itching.
• Applying emollients to the skin such as baby oil or petroleum jelly after showering

References

External links

• Frontiers in pruritus research: scratching the brain for more effective itch therapy J. Clin. Invest. 116:1174–1185 (2006). DOI 10.1172/JCI28553