Panaritium L03.1

Collective term for all purulent infections of the fingers and toes.

Depending on the location, extent and depth of the infection, a distinction is made between:

1. Paronychia (inflammation of the nail bed)
   • Acute paronychia (special case: bulla repens)
   • Chronic paronychia.
2. Panaritium subcutaneum, tendinosum, articulare, periostale (corresponds to a phlegmon).

Acute paronychia is a polymicrobial infection; it is usually caused by staphylococci. Other possible pathogens are: streptococci, Pseudomonas aeruginosa, Proteus mirabilis as well as Candida albicans. Less frequent are viruses (e.g. herpes simplex viruses) or non-infectious causes (drug-induced chronic paronychia such as after therapy with retinoids or after EGFR inhibitors).

Mostly occurring after minor injuries of the cuticle with secondary bacterial infection. Usually only 1 finger is affected. Painful, edematous swollen red area, knocking sensation, abscess. Since the finger skin is covered with a thick corneal layer, a pus can develop at different points of the digital end pahalanx, a finding known as bulla repens. The initially superficial inflammation can progress as phlegmon into the depths with spread to the tendon sheath apparatus and possibly to bony structures.

Chronic paronychia, which usually manifests itself on the thumb and index finger, often occurs due to recurrent microtrauma, sometimes during manual work in a humid environment. Diabetes mellitus can be predisposing.

Clear clinical findings; bacteriological examination, resistogram.

For uncomplicated paronychia, topical antibiotics with occlusive plaster dressings are usually sufficient. On the feet, it is also recommended to put on warm socks (Leggit JC 2017). Systemic antibiotic therapy is not necessary in these cases.

Cave: In the case of paronychia of the toenail, a differential diagnosis must be made to distinguish an unguius incarnatus, which has a different etiology and requires a different therapy (Lomax A et al 2016).

If deeper tissue areas are involved, immediate surgical repair with incision, evacuation if necessary, and drainage is usually necessary. Subsequent immobilization by means of a Böhler splint, open wound treatment, wound irrigation with quinolinol (e.g., Chinosol 1:1000 or R042 ), disinfecting wound dressings with polyvidone-iodine (e.g., Braunovidon ointment). Application of systemic antibiotics according to antibiogram.

Initial penicillinase-safe penicillins such as dicloxacillin (e.g., InfectoStaph®) p.o. 2-4 g/day in 4-6 ED.

1. Capriotti KD et al.(2019) A randomized phase 2 trial of the efficacy and safety of a novel topical povidone-iodine formulation for Cancer therapy-associated Paronychia. Invest New Drugs doi: 10.1007/s10637-019-00825-0. https://www.ncbi.nlm.nih.gov/pubmed/31240513
2. Dulski A et al (2019) Paronychia. StatPearls. Treasure Island (FL)
3. Flevas DA et al.(2019) Infections of the hand: an overview. EFORT Open Rev 4:183-193.
4. Leggit JC (2017) Acute and Chronic Paronychia.On Fam Physician 96:44-51.
5. Lomax A et al (2016) Toenail paronychia. Foot Ankle Surgery 22:219-223.