Paronychia is infection of the periungual tissues. Acute paronychia causes redness, warmth, and pain in the nail folds. Diagnosis is based on clinical examination. Incision and drainage is an important treatment modality. Antistaphylococcal antibiotics may also be used.
(See also Overview of Nail Disorders.)
Paronychia refers to infection of the periungual skin folds, and may be acute or chronic. In acute paronychia, the causative organisms are usually Staphylococcus aureus or streptococci and, less commonly, Pseudomonas or Proteus species. Organisms enter through a break in the epidermis resulting from a hangnail, trauma to a nail fold, loss of the cuticle, or chronic irritation (eg, resulting from water and detergents). Biting or sucking the fingers can also predispose people to developing the infection. In toes, infection often begins at an ingrown toenail.
In patients with diabetes and those with peripheral vascular disease, toenail paronychia can lead to more extensive infection and threaten the limb.
Symptoms and Signs of Acute Paronychia
Paronychia develops along the nail margin (lateral and/or proximal nail fold), manifesting over hours to days with pain, warmth, redness, and swelling. Pus usually develops along the nail margin and sometimes beneath the nail. Infection can spread to the fingertip pulp, causing a felon. Rarely, infection penetrates deep into the finger, sometimes causing infectious flexor tenosynovitis.
In this photo, acute paronychia is characterized by extensive inflammation around the fingernail and purulence.
Diagnosis of Acute Paronychia
Physical examination alone
The diagnosis of acute paronychia is based on physical examination.
Several skin conditions can cause changes that mimic paronychia and should be considered, particularly when treatment is not effective initially. These conditions include squamous cell carcinoma, proximal onychomycosis, pyogenic granuloma, pyoderma gangrenosum, and herpetic whitlow.
Treatment of Acute Paronychia
Antibiotics effective against staphylococci and streptococci
Drainage of pus
Early treatment is warm compresses or soaks and an oral antibiotic effective against staphylococci and streptococci (eg, dicloxacillin or cephalexin 250 mg 4 times a day, clindamycin 300 mg 4 times a day). In areas where methicillin-resistant Early treatment is warm compresses or soaks and an oral antibiotic effective against staphylococci and streptococci (eg, dicloxacillin or cephalexin 250 mg 4 times a day, clindamycin 300 mg 4 times a day). In areas where methicillin-resistantStaphylococcus aureus is common, antibiotics that are effective against this organism (eg, trimethoprim/sulfamethoxazole) should be chosen based on results of local sensitivity testing. Toe paronychia should be monitored for signs of is common, antibiotics that are effective against this organism (eg, trimethoprim/sulfamethoxazole) should be chosen based on results of local sensitivity testing. Toe paronychia should be monitored for signs ofcellulitis or more severe infection (eg, extension of edema or erythema, lymphadenopathy, fever) in patients with diabetes and others with peripheral vascular disease.
Fluctuant swelling or visible pus should be drained with a Freer elevator, small hemostat, or #11 scalpel blade inserted between the nail and nail fold. Skin incision is unnecessary. A thin gauze wick can be inserted for 24 to 48 hours to allow drainage. It is important to perform a wound culture to evaluate organisms and sensitivities.
Key Points
Acute paronychia can be related to a hangnail, nail fold trauma, loss of the cuticle, chronic irritation, or biting or sucking of the fingers.
The diagnosis is likely when severe redness, pain, and warmth develop acutely along the nail margin, but consider alternative diagnoses, particularly if treatment is unsuccessful.
Treat with an antibiotic and moist heat and by draining any visible pus.
