Cold Sores (Herpes Labialis): Causes, Triggers and Care
Cold sores are painful lip blisters caused by herpes simplex virus. Learn triggers, healing time, how to avoid spreading them and signs that need urgent care.
Condition guide
Cold sores
Also known as Herpes labialis, Fever blisters, HSV-1, Lip blisters.
In short
Cold sores are small, painful, fluid filled blisters on or around the lips caused by the herpes simplex virus, usually type 1 (HSV-1). They typically begin with tingling or burning, form blisters within about two days, then crust and heal within 10 days to two weeks. The virus stays in the body and can flare again with triggers like fever, strong sun, stress or periods, and cold sores are contagious until fully healed, so avoid kissing babies and sharing items until they heal.
Typical signs
- Tingling, itching or burning on the lip a day or so before anything is visible
- Small, fluid filled blisters on or around the lips
- Blisters that burst, crust over and usually heal within 10 days
- Sores that return in the same spot after illness, sun or periods
- In a first infection, especially in children, sores inside the mouth, swollen gums and fever
When to see a dermatologist
- A cold sore has not started healing after 10 days
- The sore is unusually large, painful or spreading
- You get cold sores very often and they affect your work or confidence
- You have eczema, are pregnant or have weak immunity
- Get urgent help for sores near the eye, eye pain, redness or blurred vision, or many painful sores spreading over eczema
- Call 112 or 108 for a baby with blisters who is feeding poorly, very sleepy or has a fever, or anyone with severe headache, confusion, drowsiness or a seizure
Signs vary from person to person and several skin conditions look alike. Only an examination can confirm a diagnosis.
Read the guides
Full, referenced articles on cold sores written for Indian skin, with answers to common questions.
Eczema in Babies: Infant Atopic Dermatitis Care at Home
Baby eczema causes dry, red, itchy patches, often on the cheeks and scalp. Learn gentle bathing, moisturising, trigger care and warning signs to see a doctor.
Worried about cold sores?
Book an online consultation with Dr. Maria Ansari for an assessment and a written care plan made for you.
This page is a short summary for general education and does not replace a consultation with a qualified dermatologist. Do not start, stop or change any medicine based on this page. Read the full medical disclaimer.