Itchy bumps are often the result of seborrheic dermatitis, states WebMD. Other conditions that cause red bumps and itchiness include folliculitis, acne keloidalis nuchae, head lice, ringworm and psoriasis, according to Skinsight.
Seborrheic dermatitis is marked by a rash as well as white specks on the hair or scalp. Seborrheic dermatitis also can affect other areas of the body, such as the ear, nose and eyelids.
The condition also is known as seborrhea or by its common name of dandruff, according to Mayo Clinic. It is treated with cortisone creams, shampoos or anti-fungal medicines. When the condition affects infants, it is known as cradle cap. The cause of dandruff, or seborrheic dermatitis is not known, according to Mayo Clinic. However, health care professionals believe reactions are triggered by the yeast infection malassezia or, in some cases, as a response to psoriasis.
Folliculitis is caused by inflammation of the hair follicles while acne keloidalis nuchae usually produces inflamed bumps on the scalp and neck, states Skinsight. Head lice is a contagious infection of the scalp that frequently occurs in schools and day care centers. Ringworm is a fungal infection that presents as scaly patches or spots of broken hair. Psoriasis, a non-contagious condition, affects about 2 percent of the U.S. population and produces red scaly patches on the scalp and skin.