Bacterial or viral infections are common causes for painful lumps on the inner thigh. These may include hidradenitis suppurativa, folliculitis, warts, herpes and syphilis.
One of the most common reasons for which a painful lump may appear on the inner thigh is hidradenitis suppurativa, a type of lesion that occurs when dead skin cells and oil block the hair follicles. The follicles become infected with bacteria. According to the Mayo Clinic, the symptoms can be made worse by stress, excess weight, excessive perspiration and hormonal changes. With basic hygiene and the use of mild soaps, the painful lump should recess in a couple of days. If the pain becomes worse or returns often, consult a doctor. Folliculitis is a similar condition that can cause bumps on the inner thighs. Caused by various types of bacteria that cause the hair follicles to become infected, folliculitis may result in itchy and painful boils. Mild cases often disappear without treatment, but if the symptoms persist, a doctor may recommend an anti-fungal cream. Warts are another reason for painful bumps on inner thighs. Wart removal may be necessary to alleviate the condition. If the painful lumps on the inner thigh are caused by herpes or another STD like syphilis, they usually disappear with medication for the underlying disease.