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Non‐inflammatory onycholysis from formaldehyde‐containing nail hardener

A white female aged 61 years was seen in May 1978 for the onset of onycholysis of the L1 and R5,4,3,1 fingers of 3-4 weeks' duration. For 2 months prior to the onset she had been using a liquid nail hardener daily. She stopped application of the nail hardener shortly after the nail changes began. She had purchased the nail hardener in Vancouver. The Canadian distributor obtained from the manufacturer in Switzerland the ingredients which were written as follows: Formaldehydum 4.5 vol. % Tinct. Allii sat. Extr. Chamomillae Aqua Hamamelidis (Witch Hazel) Excip. ad. solut. A patch test was carried out to formaldehyde aqueous 2 % on the upper back and at day 2 a vesicular response was observed and graded 2. During the latter part of May she developed cellulitis of the R5 finger and in mid-June 1978 the R5 fingernail became loose and then separated. The patient was called in for re-examination in January 1981 and she stated that the nails had taken a little over a year to return to normal. On examination, they appeared within normal limits. A patch test to formaldehyde aqueous 2 % produced a negative response. It appeared that the onycholysis was brought about by the application of the nail hardener. Apart from the cellulitis there was no inflammatory reaction in the skin around the nails. One can postulate that the formaldehyde entered the nail plate and produced an inflammatory reaction in the nail bed, leading to the separation of the nail plate from the bed. This case was noted briefly by Fisher (1979) but the history is here corrected. A follow-up is added. Recovery of the nails after stopping the use of the hardener further tends to implicate it. Evidently the formaldehyde contact sensitivity became lost during 2Yz years. Formaldehyde-containing nail hardeners have been known since 1966 to be capable of producing nail changes. Although this patient suffered only a simple onycholysis without inflammation, other reports detail much more severe reactions from the formaldehyde component of nail hardeners. Such reactions include subungual haemorrhages, discoloration of the nail plate, and even lip haemorrhages in nail biters (Fisher 1979). According to Brauer (1980) there is no free formaldehyde from newer nail hardeners which contain toluene sulphonamide formaldehyde resin, and on good grounds he questioned the validity of a report of onycholysis in two cases attributed to the resin by Palzik & Enscoe (1980). No cases of nail damage from the resin have been observed (Fisher, A. A., cited by Brauer 1980). Nail hardeners containing free formaldehyde have not been available in the United States for more than a dozen years (Brauer 1980). It appears that nail hardeners produced in the United States are safe but that one should beware of imported products. It is not clear whether formaldehyde-free nail hardeners are still made in, as opposed to imported into, Canada. Enquiries are being made.