Red bumps can develop on the knees for a variety of reasons. These bumps can be painful, irritating and unpleasant in appearance. Although bumps on the knees are not typically cause for alarm, it is important for the sufferer to understand what kinds of conditions can cause them — and what treatments are available.
Red bumps on the knees can be accompanied by a change of texture to the skin. The bumps can be scaly, patchy, bright in color and blister-like. In addition, they may contain a pus material that can ooze and result in a crust over the top of the bump. The skin on and around the bump can also become inflamed and sensitive to the touch.
The MedlinePlus website notes that red bumps on the knees can be due to contact dermatitis, which is when the skin encounters an irritating substance. Among these substances include rubber, latex, soaps, detergents, dyes in clothing or poison ivy. Red bumps can also be caused by skin conditions such as psoriasis or eczema. Sometimes shaving can cause ingrown hairs or staph infections such as barber's itch, which can result in red bumps on the knees.
To treat red bumps on the knees, a doctor or dermatologist may suggest an emollient moisturizer that can help soothe itchiness and keep moisture in the skin. Antihistamines or calamine lotion can also be beneficial, especially if the red bumps are associated with an allergen or an irritating object like poison oak. A warm compress can help soothe the skin and encourage drainage. A doctor may also prescribe an antifungal medication or a topical or oral antibiotic.
According to the KidsHealth website, it is possible to avoid red bumps from developing on the knees in many cases. The sufferer should avoid irritating substances such as nickel or fragrant body products. Eczema symptoms can be reduced by avoiding hot showers, harsh soaps and exposure to the sun. Red bumps caused by barber's itch or ingrown hairs can be reduced by using a fresh, sharp razor and not pulling the skin taught with every shave.
The AskDrSears website warns that some types of rash-like bumps on the knees require immediate doctor's attention. One of these rashes, called petechiae, occurs when the blood vessels beneath the skin rupture. The skin may look as if a red ink pen was used to draw tiny dots on the surface of the skin. Another dangerous rash, purpua, develops similarly but the coloring of the spot can be darker in appearance.