Paronychia is infection and inflammation of the paronychial tissues (nail fold) of the fingers or, less commonly, the toes. Acute paronychia, in most cases, involves bacterial infection which may progress into pyogenic (pus forming) abscess.
The most common infecting organism in bacterial pyogenic paronychia is Staphylococcus aureus. Other Streptococcus species, Pseudomonas species, Gram-negative bacteria and anaerobic bacteria may also be the causative organisms. These pathogens enter the paronychial tissues when there is physical or chemical damage to the nail fold. When treated, acute form of bacterial paronychia usually resolves within 2-3 weeks and usually does not recur. If there is no fluctuance (presence of pus) the infection may resolve with warm soaks. If the infection is pyogenic, oral antibiotic therapy and surgical drainage may help in resolving the condition.
Causes of acute paronychiaTrauma, physical damage, irritation and chemical damage to the cuticle or nail fold is the main factor associated with the development of pyogenic paronychia. Damage to nail fold may occur from dropping of heavy objects on toes or fingers, manicure procedures, biting or picking at cuticle or hangnail, ingrown nail, dishwashing or any sharp object cutting or piercing into nail fold tissue. Such damage to the paronychial tissues or cuticle allows the entry of pyogenic pathogens.
Certain habits like nail biting, biting or picking at a hangnail or finger sucking may also give rise to pyogenic bacterial infection of the paronychial tissues. Exposure to saliva and oral flora, will facilitate the entry of several anaerobic gram-negative pyogenic bacteria into paronychial tissues.
The most common infecting organism in this acute pyogenic infection is Staphylococcus aureus. Other causative organisms include Streptococcus pyogenes, Pseudomonas pyocyanea, Proteus vulgaris, other Streptococcus species, Pseudomonas species, Gram-negative bacteria and anaerobic bacteria.
Signs, symptoms and clinical manifestationsIn acute pyogenic paronychia, typically only one nail is involved. The signs include reddening (erythema) and swelling (edema) of the proximal and lateral nail folds. Initially, it presents as superficial bacterial infection. Later it becomes pyogenic with accumulation of purulent material under the nail fold. The symptoms include extreme pain, pressure, discomfort and tenderness. The patient gets great relief when the pus is drained. An untreated acute paronychia may progress to infect the nail matrix leading to permanent dystrophy of the nail plate.
|picture of acute, bacterial, pyogenic paronychia|
Diagnosis of acute paronychiaThe history of recent minor trauma and physical examination of nail folds will help in the diagnosis of acute paronychia. In early stages, the digital pressure test may be helpful in determining the presence or extent of an pyogenic abscess. The affected area gets blanched and helps in clear demarcation of the abscess. In bacterial paronychia not responding to antibiotics, methicillin-resistant S. aureus (MRSA) infection should be ruled out. Psoriasis, reactive arthritis, dactylitis and herpetic whitlow may have to be differentiated from acute pyogenic paronychia.
Bacterial paronychia treatmentMild paronychia can be treated at home by soaking the infected nail in warm water or dilute vinegar solution for 3-4 times a day. Acetaminophen or a nonsteroidal anti-inflammatory medication may be taken orally to provide relief from pain and inflammation. A combination of topical antibiotic and corticosteroid cream may be applied. The bacterial infection may heal on its own in a few days.
If the paronychia persists after a week or becomes acute and pyogenic, it requires medical intervention. Persisting infection can be treated by oral antibiotic therapy and surgical drainage. A broad-spectrum oral antibiotic may be prescribed.
To drain the pus, the nail fold is lifted with a 23-gauge needle. This helps in passive draining of the accumulated pus. Mild pressure may be applied on the infected area to facilitate draining. Alternatively a small incision may be made with a scalpel to open up the paronychia abscess and clean it of pus. In severe acute bacterial pyogenic paronychia, the infection may involve nail bed and need partial or complete nail removal.
References for acute bacterial pyogenic paronychia:|
1.Rigopoulos D, Larios G, Gregoriou S, Alevizos A. Acute and chronic paronychia. Am Fam Physician. 2008 Feb 1;77(3):339-46.
2.Shafritz AB, Coppage JM. Acute and chronic paronychia of the hand. J Am Acad Orthop Surg. 2014 Mar;22(3):165-74.