Pendulum Metal Hypersensitivity: What Are We Missing?

Metal hypersensitivity affects 10-15% of foot and ankle patients, usually presenting with an eczematous-type rash overlying metallic implants and representing a type IV delayed hypersensitivity reaction. 

Relevance of jewelry allergy

A history of jewelry or contact allergy is an important clue. Research shows that 60% of patients with prosthesis-related hypersensitivity (PRH) patients had a known contact allergy – 25.7% to metals and 34.6% to other substances.

In a patch testing study, nickel is the most frequently identified allergen (31.5%), followed by vanadium chloride (13.7%) and gentamycin, an antibiotic often added to bone cement.

Current recommendations

There is no accepted protocol to evaluate and manage patients with suspected metal hypersensitivity reactions. Likewise, no orthopedic society or governing body has established preoperative screening guidelines for identifying at-risk patients. What we do have to guide us is a consensus statement from a panel of experts:

Implant allergy is rare but should be considered in cases of persistent, unexplained symptoms. Patch testing with late reading may be useful; lymphocyte transformation testing not recommended. Routine preoperative screening without a history of allergy is unnecessary.