Water blisters on the legs in older adults: what to know

A blister is a pocket of fluid beneath or within the outer skin. Friction, a contact reaction, sun exposure, or an infection such as shingles or chickenpox can produce blisters. Some blistering illnesses also occur more often later in life. Location, pain, itch, redness, and whether lesions appear in a stripe or in scattered groups help a clinician narrow the cause. A blister is a presentation of several conditions; its presence alone does not identify one diagnosis.

Wash gently with lukewarm water, pat dry, and cover the intact blister with a clean non-stick dressing. Avoid rubbing, tight clothing, and adhesive directly on the blister. Do not deliberately puncture it. If it opens, let fluid drain naturally, keep the loose skin in place, and cover it; wash your hands before and after dressing changes. A clinician can advise whether testing or treatment is needed. Read about [Skin Blisters](/symptoms/skin-blisters/) and possible [Contact Dermatitis](/conditions/contact-dermatitis/).

Arrange prompt medical assessment if blisters are spreading, very painful, recurrent, or surrounded by increasing warmth, redness, swelling, or drainage. Seek urgent help for fever, confusion, marked weakness, a blistering rash near the eyes, or difficulty eating or drinking. Older adults and people with diabetes, poor circulation, or reduced immunity should contact a clinician early because a small wound may heal slowly. A one-sided band of painful blisters may fit [Shingles](/conditions/shingles/), which can require timely treatment.

Ask what pattern the blisters suggest, whether a swab or skin examination is needed, how to dress an opened area, and which medicines or products should be avoided. Mention recent new creams, footwear, heat, sun exposure, pain, itch, and every medicine being taken.