Insects may bite exposed skin like the lower part of your arm. These bites often produce bumps that result from localized swelling. Genetic skin conditions like keratosis pilaris can also produce bumps on the skin of your lower arm that feel like sandpaper. Skin conditions like ichthyosis vulgaris or atopic dermatitis may be associated with keratosis pilaris bumps. See your doctor any time unexplained changes happen to your skin or if your condition gets worse.
Causes
Insect bites or keratin deposits at the surface of your skin may cause bumps on your lower arm. Venom from fire ants, bees, wasps and hornets that bite or sting your arm may cause bumps on your lower arm. Mosquito, flea and mite bites can also swell and produce bumps. Keratosis pilaris may cause rough patches of bumps on the lower part of your arm and may also affect skin on your thighs or buttocks. Keratosis pilaris occurs when keratin builds up and forms hard plugs in your hair follicles.
Symptoms
Insect bites typically produce bumps within minutes after you are bitten. The bites may redden, swell, itch or be painful. Insect bites can cause burning, numbness or tingling. Keratosis pilaris may produce many small bumps at the hair follicles on the lower part of your arm. These bumps are dry, rough and skin-toned. Keratosis pilaris bumps are usually painless but may itch, redden or swell occasionally. Dry skin may worsen keratosis pilaris.
Treatment
Remove insect stingers if they remain lodged in your skin. Wash insect bites with soap and water then ice these bumps for 10 minutes. Remove the ice for 10 minutes and repeat with another 10-minute application of ice. Oral antihistamines and topical anti-itch creams can help suppress itching from insect bites. According to the Mayo Clinic, treatment for keratosis pilaris focuses on softening keratin deposits in your skin. Topical exfoliant products that contain alpha-hydroxy, lactic acid, salicylic acid or urea can moisturize your skin and help you shed dead skin cells. Topical retinoids promote skin cell turnover and may prevent the accumulation of keratin at hair follicles on your lower arm. Do not scrub or remove these bumps.
When to Seek Medical Attention
Severe reactions to insect bites may require medication attention. Seek medical attention for insect bites if you have trouble breathing or experience swelling around your face and mouth. You may feel tired if you have a severe reaction to insect bites. Severe reactions to these bites can produce a tight sensation in your throat, and your skin may develop a pale shade of blue. Keratosis pilaris may not require medical attention. You may seek medical attention if you are concerned about the appearance of these bumps or if they do not respond to over-the-counter moisturizing products.
Prevention
Prevent insect bites that cause bumps on your arm by avoiding areas with known concentrations of insects. Avoid quick jerky movements around insect hives and nests. MedlinePlus advises against wearing perfume, floral print or dark clothing. Apply insect repellent to your body and use candles or repellent oils. Keep food sealed and covered if you eat outdoors.
Prevent keratosis pilaris bumps by gently patting your skin dry after showering. Do not rub your skin. Apply moisturizers to your skin while it's still moist after bathing or showering. Apply lactic acid creams to your lower arms to help remove excess keratin from your skin. Consider using a humidifier in your home or office to help moisturize the air in your environment.
