A 51-year-old male took advantage of a readjustment of his lower-leg prosthesis to have it revarnished on the exterior and the upper part of the interior. Use of the newly-varnished prosthesis coincided with the appearance of pruriginous papulo-erythematous lesions in the area of the amputation stump and thigh with, in some places, hyperkeratotic lesions. Itchy lesions spread to the hands, upper limbs, left lower limb and trunk, sparing the face and scalp. After ceasing use of the prosthesis, the patient improved greatly.He was patch tested with the GEIDC standard series, our prosthesis series, a plastics and glues series (Chemotechnique), and a meth(arylate) series (Chemotechnique), with positive ( + +) reactions at 48 and 96 h to: methyl methacrylate (2%), ethyl methacrylate (2%), hydroxyethyl methacrylate (2%), hydroxypropyl methacrylate (2%), methacrylic acid (0.1 %), acrylonitrile (0.1 %), butyl methacrylate (2% ), butyl acrylate (0.1% ), ethylhexyl acrylate (0.1% ), hydroxypropyl acrylate (0.1% ), ethyleneglycol dimethacrylate (2%), triethyleneglycol dimethacrylate (2%), butanediol dimethacrylate (2%), urethane dime_thacrylate (2% ), and triethyleneglycol diacrylate (0.1 %), all pet.In general, prostheses cause few problems other than traumatic (friction). This sensitization was caused by high-resistance varnishes, which are usually of 2 types: (i) polyurethane resins (isocyanates), associated with acrylic and methacrylic resins; (ii) polyurethane resins associated with polyester resins.At present, formaldehyde and phenol-formaldehyde resins, and above all, paratertiarybutylphenolformaldehyde resin, are scarcely used.Chemists comment that sensitization is produced because resins in the varnishes are not completely cured.Prevention of cases of contact dermatitis consists in adequate treatment and lining the interior of the prosthesis with Teflon and/or silicone.Recently, Foussereau et al.(1) described the first case of dermatitis, caused by an amputation prosthesis (above-knee), to be attributed to methacrylic resins, with positive patch tests to methyl methacrylate and triethyleneglycol dimethacrylate (both 2% pet.).
