What is paronychia?
Paronychia (whitlow) is an inflammation of the nail fold or the cuticle. It is common and has various causes. An acute form is distinguished, which arises very suddenly, and a chronic form, which develops more gradually and usually persists longer.
How does it develop?
Acute paronychia: infection with a bacterium (usually Staphylococcus aureus). The bacterium has entered the tissue through damage to the skin or cuticle. Well-known examples of such damage are an accident with nail scissors, a splinter under the cuticle, or pulling off (or biting) loose bits of skin at the cuticle. Nail biting can also cause an inflammation of the nail fold.
Chronic paronychia: this form arises in people who have long-term damage to the cuticles, for example from frequent, prolonged contact with water and cleaning agents that soften the skin around the nails and make it accessible to micro-organisms. These infections are usually caused by a yeast (Candida albicans, Candida parapsilosis) or sometimes a bacterium (Pseudomonas aeruginosa).
What does it look like?
Acute paronychia: swollen, red and (pressure-)painful nail folds with pus formation. Chronic paronychia: swollen, red and painful nail folds, with an eczema-like change and scaling; pus is usually absent. With long-standing paronychia there is also discolouration and poor growth of the nail plates.
How is the diagnosis made?
The diagnosis is made by eye. To determine the cause, a culture of the pus can be taken.
How is it treated?
Acute paronychia: when pus has collected in the nail fold, it must be removed. The doctor can relieve the inflammation by incising the abscess and letting the pus drain, or often by lifting the cuticle with a small surgical instrument. If needed, an antibiotic course can also be prescribed. Especially in children, prompt treatment is warranted to prevent lasting damage to the nail apparatus.
Chronic paronychia: treatment focuses on restoring the cuticles. Avoiding excessive water and soap use is very important so the cuticles can recover. Depending on the micro-organism, topical treatment of the cuticles with an anti-yeast or antibacterial ointment is often warranted. For persistent chronic paronychia, an oral course of antifungal medicine or antibiotics may be needed. Chronic paronychia in particular often proves very persistent and can last many months despite adequate therapy.
When to see a doctor
See a doctor if a nail fold becomes red, swollen and painful with pus (which may need draining), or if a chronic red, scaly change of the nail folds does not settle with good hand protection.