An infection of the skin folds around the nail plate, otherwise known as a paronychia , is one of the most common infections in the pediatric hand. Both acute and chronic forms of paronychia exist. While the acute infection can often be associated with a “hangnail,” nail biting, splinters, or other minor trauma, the chronic infections are often the result of a persistently moist environment. In children, this is usually the result of persistent thumb or digital sucking (Harness and Blazar 2005; Stone and Mullins 1968; Rayan and Turner 1989). In addition, acute infections may present superimposed on a chronic infection.

It is important to determine historically whether or not a chronic infection is present, as the microbiology associated with a chronic paronychia is significantly different from that of an acute paronychia. As such, the treatment is also different. In the acute form, Staphylococcus aureus is the usual causative organism. However, because the etiology of paronychia in children can be digital sucking, a mixed organism infection or atypical organisms may be present. For chronic infections, atypical organisms such as fungi are usually implicated.

The typical presentation of a paronychia is localized pain, erythema, and swelling along the paronychial fold. While these infections are most commonly found on only one side of the nail plate, they can sometimes progress around the proximal (eponychial) fold to include the other side in a “runaround” abscess (Green et al. 2011).

Treatment of acute paronychia in children is similar to the treatment in adults (Table 4). If it is caught in the earliest stages and only localized erythema is present without obvious fluctuance or purulence, then treatment with oral antibiotics, elevation, and warm compresses is appropriate with close observation. However, if this treatment has not been effective after 24 h or if there is any evidence of purulence, then a more aggressive approach is warranted. If the patient is able to tolerate a local digital block, then this method is preferred. However, in young children the use of conscious sedation can relieve the anxiety of both the child and the parents.

Once anesthesia is achieved, surgical drainage is performed. The method of drainage depends on the location of the purulence, with the bottom line of achieving complete surgical drainage of any underlying purulence. In simple paronychia localized to the paronychial fold, a Freer elevator can be used to gently develop the plane between the nail plate and the paronychia, or alternatively, a longitudinal incision in line with the paronychial fold is adequate to relieve tension. Once the infection progresses, purulence can track underneath the nail plate. If this is seen, partial or complete nail plate removal is necessary. Depending on how proximally the infection tracks, the eponychial fold can also be lifted through the use of longitudinal incisions in line with the paronychia (Fig. 3).

In the case of a chronic paronychia, the offending organism must be identified. The clinical course of a chronic paronychia is often indolent, with periodic flares of symptoms that do not rapidly progress as in the acute infection. Treatment is often difficult because of the mixed microbiology responsible for these infections, which can include bacterial, mycobacterial, and fungal components.

The mainstay of treatment for chronic paronychial infections is topical creams that contain a combination of antifungals and steroids (3 % clioquinol in triamcinolone-nystatin mixture). However, in refractory cases, marsupialization is necessary. Marsupialization involves removing a full-thickness, crescent-shaped segment of the skin proximal to the eponychial fold (a “pocket”) that is then allowed to freely drain and heal by secondary intention. This procedure is done with or without the removal of the nail plate depending on the involvement of the nail bed and the nail plate itself (Canales et al. 1989; McDonald et al. 2011; Green 2005).

Surgical treatment is performed under local anesthesia with or without conscious sedation or under general anesthesia (Table 5). There is no agreement on the optimal incision for surgical drainage, though the author’s preference is for a high lateral incision placed just below the level of the nail plate on the affected side (Fig. 4). This incision prevents disturbance of the volar fat pad and neurovascular bundle. Though in many cases, the placement of the incision is based on the location of a traumatic wound, when possible, careful consideration of the placement of the incision can avoid significant postoperative morbidity. Thumb and small finger incisions are best made radially, while other digits should be approached from the ulnar side to avoid the primary areas involved in pinch. Once the incision is made, aggressive spreading with a small hemostat or dissecting scissors is necessary to break up any septa and ensure a complete surgical decompression. A small drain should be left in place for a day or two to prevent additional accumulation. Splinting, strict elevation, and appropriate antibiotics are then initiated. When there is clinical evidence of improvement, usually at about 48 h after drainage has been performed, the drain is removed and the wound is allowed to heal by secondary intention. A standard postoperative protocol can be found in Table 7.