Answer
Jul 28, 2026 - 01:54 PM
Cantharidin blisters usually dry up and heal within about 4–7 days. Larger or deeper blisters—especially on the feet or other pressure areas—may take 1–3 weeks to heal completely. Temporary redness or skin discoloration can last longer.
Avoid popping or peeling the blister. Keep it clean and follow the wash-off and wound-care instructions provided by your clinician, since timing varies by cantharidin formulation.
Contact your healthcare provider if you develop severe or worsening pain, spreading redness, warmth, pus, fever, or a blister that is unusually large or not improving after about two weeks.
