GLASGOW, SCOTLAND — Onychocryptosis poses a particular risk to patients with rheumatoid arthritis being treated with biologics, so vigilance should be practiced in the foot care of these patients, reported Heidi J. Davys.
Onychocryptosis can be accompanied by local sepsis, which is a serious concern in patients on anti-tumor necrosis factor-? therapy, Ms. Davys noted in a poster session at the annual meeting of the British Society for Rheumatology.
The full extent and impact of foot problems in these patients is not clear, but a retrospective 14-month audit in the rheumatology foot clinic at Leeds (England) General Infirmary identified nine cases of onychocryptosis developing in rheumatoid arthritis (RA) patients on biologic therapy.
Five of the affected patients were female, their mean age was 43 years, and the mean disease duration was 10.9 years. Etanercept was the drug being used in seven cases, and infliximab and abatacept each were being used by one patient.
None of the patients had experienced previous episodes of onychocryptosis. The mean time between commencement of biologic therapy and symptom onset was 20 weeks, wrote Ms. Davys, who is a specialist in rheumatologic podiatry, Leeds Teaching Hospitals NHS Trust.
Therapy with the biologic was suspended in all patients prior to nail treatment for an average duration of 2 weeks, until healing was complete. Eight of the patients underwent partial or total nail avulsion, three with matrix phenolization to prevent regrowth. All patients also were treated with systemic antibiotics.
The outcome was successful in all nine patients, allowing reinstitution of biologic therapy.
Promptly referring the patient to a podiatry service is considered necessary if onychocryptosis develops in a patient on biologic therapy. Podiatrists performing surgical procedures such as avulsion should be aware of current perioperative guidelines and should work closely with the rheumatology team, wrote Ms. Davys.
Surgery by a podiatrist is often required to repair onychocryptosis. Courtesy Heidi J. Davys
Some Biologics, Surgery Don't Mix
Perioperative management of patients taking immunosuppressive drugs has been a challenging issue, requiring a balance between maintaining disease control and avoiding potential morbidities such as infection. Concerns are particularly significant with the biologic response modifiers, because of the risk of serious infection associated with their use.
The published treatment guidelines are based on the perioperative use of infliximab among patients with Crohn's disease and on animal model and tissue culture investigations. Until more evidence-based clinical trial data are available, the following are considered reasonable:
▸ Infliximab. This drug can be continued without interruption or discontinued 1 week before surgery and resumed 1–2 weeks after.
▸ Etanercept and anakinra. No human data are available. Experiments in animal models suggest that these drugs should be withdrawn the week of the procedure and resumed 1–2 weeks later.
▸ Adalimumab and rituximab. No data are available. These agents should be discontinued at least 1 week before surgery and resumed 1–2 weeks later.
Source: Curr. Opin. Rheumatol. 2004;16:192–8.