Brown spots on the side of the foot: what to know

Look at whether the mark is flat or raised, evenly coloured or varied, and stable or changing. Repeated rubbing from footwear, a minor injury, or a previous rash can leave darker pigment after the skin settles. A mole or another pigmented lesion is also possible. A photograph beside a ruler can help you remember its appearance, but it cannot identify the cause.

Keep footwear comfortable and avoid rubbing the area. Do not scratch, cut, bleach, or apply strong peeling products to the spot. Arrange a routine dermatology assessment if it is new, persistent, or difficult to view. If the area is exposed in sandals, use broad-spectrum sun protection and cover it when practical. More information about related skin bumps is available under Pimples.

Seek prompt medical review if the spot changes in size, outline, or colour; develops several shades; bleeds, crusts, or becomes persistently sore; or looks unlike your other marks. Arrange earlier assessment when it sits on the sole or edge of the foot and is hard to monitor.

Ask whether the mark appears related to friction, injury, inflammation, or a pigmented lesion; whether dermoscopy would help; and which changes should trigger a faster review. Mention when you first noticed it and any new footwear, rash, trauma, or treatment.