Chapter: Consultation hour
Article: 4 of 12
Update: Feb 24, 2021
Author(s): Wohlgemuth, Walter A.
Nail bed inflammation is a common and very unpleasant disease, mainly caused by small injuries to the skin near the nail in the case of malformed nails or inadequate nail care. Synonyms often used are panaritium, felon or paronychia, or whitlow, depending on the location. The cuticle immediately surrounding the nail (onychia or panaritium subunguale) or the wall at the nail edge (paronychia or panaritium parunguale) can be affected.
Initially, there is local swelling, followed by the typical signs of inflammation: redness, warmness and pain. Acute nail bed inflammation can go as far as pus formation (mostly staphylococci). In extreme cases, even the underlying bone can be affected. In the chronic form, usually caused by the yeast fungus Candida albicans, discoloration and dystrophy of the nail itself or the nail fold often follow.
The source of the nail bed inflammation is therefore a small skin injury that allows bacteria or fungi to penetrate. This can and must be avoided by adequate nail care. This includes injury-free cutting of the nails (requiring suitable tools and the necessary caution), as well as choosing the right shape of cut (straight across for the toenails, unlike the fingernails), particularly for incorrectly grown (dysplastic) nails around skin injuries. Ingrown nail margins must be prevented.
Classic risk factors for nail bed infections (immunodeficiency, diabetes mellitus, cardiocirculatory disorders, inappropriate footwear, skin diseases) are usually not present in patients with vascular anomalies.
In patients with edema (usually with lymphatic or venous malformation) or local overgrowth of the soft tissue (e.g., Klippel-Trénaunay syndrome, Parkes Weber syndrome, CLOVES syndrome, Proteus syndrome, etc.) with enlargement of soft tissue parts of the toes, the boundaries of a toenail can very easily become overgrown.
The increased soft tissue masses then press against the lateral edge of the nail and lead to a local chronic pressure sore. This is aggravated by the increased tissue fluid pressure caused by chronic venous hypertension or lymphedema. Then the edge of the nail is no longer easy to keep clean, and a local infection often develops over time. Absolute cleanliness of these sensitive areas where there is increased soft tissue is necessary, with very careful nail cleaning and cutting. Nail care and trimming of toenails that are often additionally dysplastic can be very difficult, especially in cases of severe accompanying overgrowth. In these cases, professional nail care (podiatry) may also be useful and necessary. Specialists help patients learn appropriate nail care techniques, which they can then continue themselves.
These forms of chronic nail bed inflammation are very common and particularly persistent in many patients with vascular anomalies in the leg or foot, often beginning in childhood.
Walking barefoot should always be avoided in the case of acute, recurrent nail bed inflammation.
All circumscribed pressure points in the area of the toes, e.g., due to improperly fitting shoes, should be avoided. Local pressure relief must be achieved here, otherwise the inflammation cannot heal on account of the additional external pressure.
In order to relieve the accompanying high tissue pressure caused by edema, longer periods of standing and sitting or strenuous long-term physical exercise should be avoided in the acute phase. If possible, keep the foot at rest and elevate it during acute inflammation.
Foot baths applied twice a day (first with chamomile, and with disinfectant solutions for more severe inflammation) are indicated.
Regular locally disinfecting measures (bathing the foot in disinfectant solution) are also necessary in the case of acutely open, inflamed nail edges in order to prevent infection of these small wounds. This should be repeated daily in the acute stage. Application of polihexanide 0.1% gel locally under a plaster is helpful in case of infections. Then the affected area should be covered with bandages, which should be changed daily.
In the case of deeper-lying, chronic infections, local or even systemic antibiotic therapy or antifungal therapy according to the doctor’s instructions may be necessary before final treatment. In this case, it is imperative to exclude possible osseous involvement of the phalanges (especially the end phalanx); an X-ray may be necessary for this purpose. The complication of bone involvement with osteomyelitis usually does not heal without invasive measures, generally in combination with antibiotics.
For purulent nail bed inflammation, ointments containing ammonium bituminosulfonate are also recommended. In addition to the disinfectant effect, the inflamed skin area should also be softened so that pus can drain more easily. For basic principles of appropriate wound care, see there.
In the presence of active bacterial nail bed inflammation, a swab is necessary for microbial detection and antibiotic resistance testing. Thereafter daily foot baths with antiseptic solution. If necessary, also daily antifungal foot powder or foot ointment.
In cases of larger chronic nail bed inflammation, local surgical excision of the wound and the lateral nail and nail bed with soft tissue reduction can first be attempted. However, the long-term results, e.g., of Emmert plastic (nail wedge excision) with partial removal of the nail matrix and narrowing of the nail, are unfortunately relatively poor in patients with vascular anomalies and local overgrowth at the toes. Recurrences are common on account of the pathophysiology involving local excess of soft tissue and chronically increased pressure against the hard edge of the nail, together with the high local fluid tissue pressure (lymphedema or venous hypertension/phlebedema). In the case of chronic severe nail bed inflammation in this constellation, permanent surgical removal of the entire toenail including the nail bed is therefore advisable at an early stage in order to prevent regrowth and recurrent inflammation.
The surgical methods are regularly quite helpful in chronic nail bed inflammation and are sometimes applied too late in patients with vascular anomalies or soft tissue hyperplasia of the toes. A pain-free life without a toenail is often preferable to the alternative.