Bump under the skin at the base of the penile shaft

A tender bump around a hair-bearing area can occur with Folliculitis, particularly after friction, sweating, or hair removal. Keratosis Pilaris causes many small rough follicle-centred bumps rather than one deep lesion. Heat Rash may cause clusters in warm, occluded skin. Lichen Planus can cause itchy, flat-topped or purplish bumps. Milia are small, firm, pale cysts. A bump can also be a blocked pore or other benign lesion. The appearance alone cannot confirm the cause, and a genital bump should not be assumed to be sexually transmitted or harmless without assessment.

Do not squeeze, puncture, or freeze the area yourself. Clean gently, keep it dry, and choose loose underwear while you watch for change. Pause shaving and reduce friction until the skin settles. Record its size, colour, tenderness, surface, and whether it changes with erection or movement. If itching is prominent, ask a clinician whether an Antihistamine Treatment is appropriate; do not apply products inside the urethral opening.

Seek prompt care for severe pain, increasing redness or swelling, pus, fever, a rapidly enlarging lump, ulceration, bleeding, or difficulty passing urine. Arrange a sexual-health or dermatology review if the bump follows sexual exposure, multiple lesions appear, it lasts beyond a short period, or it repeatedly returns. Urgent assessment is needed for sudden severe testicular pain or swelling, even if the skin bump seems separate.

Is this arising from a hair follicle or deeper tissue? Should I have infection or sexual-health testing? Would observation be enough, and when should a persistent lesion be removed or sampled?