Skin dimpling under the armpit: what to know

Dimpling or puckering means the skin is being pulled inward or has developed an unusual contour. It may be related to a benign change, an old scar, inflammation, a blocked gland or altered tissue beneath the skin. The armpit also contains lymph nodes and breast tissue extends toward it.

Breast cancer can present with skin dimpling, although a symptom does not establish its cause. Paget Disease of the Breast more often affects the nipple or areola, but any associated nipple or skin change should be described during assessment.

Compare both sides in good light and note whether the indentation changes when you raise your arm or move your shoulder. Do not repeatedly press the area, as this can make it sore. Arrange a clinical appointment, especially if the change is new, persistent or becoming more visible.

Record any lump, breast shape change, nipple inversion, discharge, rash, pain or recent injury. The clinician may examine the breast and armpit and decide whether imaging or another test is appropriate.

Seek prompt assessment for dimpling with a new lump, skin thickening, redness, warmth, nipple discharge, a new inverted nipple, an ulcer, or swelling in the armpit. Seek urgent care for rapidly spreading redness, severe pain, fever or feeling acutely unwell.

Ask what might be pulling the skin inward, whether the breast and lymph nodes need imaging, and which changes should be reported quickly. Mention when you noticed it, whether it is one-sided, and any family or personal breast history.