Infected nail folds (paronychia)

What it is

Paronychia is infection of the skin folds around the nail.

How it works

Bacteria or yeast enter through damaged cuticles.

Why it matters on darker skin

Redness may look dark or purple on dark skin.

Causes and triggers

Cuticle cutting, biting, wet work.

What helps — and why it works

Warm soaks: relieve pain. Expected timeline: days. Doctor if pus or spreading: may need drainage or antibiotics.

More detail

Acute paronychia develops over hours to days, usually after a hangnail, nail biting, a manicure that cut the cuticle, or a small injury. Bacteria such as Staphylococcus get in, causing a hot, throbbing, swollen fold that may collect pus. Chronic paronychia builds over weeks in people whose hands are often wet — cooks, cleaners, hairdressers, and those washing many dishes — and is linked with yeast and irritation. The cuticle disappears, the fold becomes swollen and tender, and the nail may develop ridges. For acute cases, warm soaks several times a day can help small infections drain; a clinician may need to drain an abscess or prescribe antibiotics. Chronic paronychia needs the cuticle to recover: keep hands dry, wear cotton-lined gloves for wet work, moisturise, and see a doctor for prescribed creams. Never push back or cut the cuticle while it heals.

What to avoid and why

Avoid cutting cuticles.

Common mistakes

• Ignoring spreading redness.

Everyday nail habits

Healthy nails depend on protecting the nail matrix — the growing area hidden under the cuticle — and on limiting cycles of wetting and drying. Wear gloves for washing and cleaning, keep nails short and filed in one direction with a fine file, and moisturise hands, nails and cuticles after washing and at night. Leave the cuticle in place: it is a seal that keeps water and germs away from the matrix, and cutting it is a common cause of infection. Fingernails grow about three millimetres a month and toenails about one, so a new fingernail takes four to six months and a toenail up to eighteen months; any treatment needs at least that long to judge. Choose salons that sterilise metal tools between clients, or bring your own. Take breaks between gel or acrylic sets, and never peel coatings off. Because polish can hide important changes, look at bare nails regularly, particularly for a new dark band, a lifted nail or a change in shape.

Products and treatments

Many nail products make claims with little evidence. Moisturisers containing urea, lactic acid or petrolatum have the most support for dry, brittle nails and cracked skin around them. Formaldehyde-based hardeners can make nails more brittle over time and can cause allergy, so we do not recommend them. Antifungal nail lacquers such as amorolfine or ciclopirox can help mild fungal infection limited to the tip of one or two nails, but only after the diagnosis is confirmed — many thick or discoloured nails are not fungal at all. Biotin supplements are widely sold; evidence is weak and high doses can interfere with some blood tests. If you have diabetes or poor circulation, foot and toenail problems deserve early professional care.

Questions to ask your doctor or pharmacist

Useful questions include: What do you think is causing this? Is it likely to come back, and how can I prevent it? Which products should I stop? How long before I should expect improvement, and when should I come back if it isn't better? Are there side effects to watch for? Is this treatment safe if I am pregnant, breastfeeding or for my child? Writing your questions down, bringing your products (or photos of their labels) and taking dated photos of the problem make an appointment much more useful.