Abstract
To the Editor:
Acrylates are increasingly being used in nail cosmetics. We report a case of nail acrylate contact allergy with isolated nail dystrophy as the clinical presentation.
A 28-year-old air stewardess was referred for “onychomycosis” of her fingernails. These nail changes had started insidiously 6 years ago when she had to apply nail polish consistently for work purposes. The patient used home-cured acrylate-based gel nail polishes regularly, with artificial press-on nails once prior to presentation.
On examination, all the patient’s fingernails were dystrophic with distal onycholysis, subungual hyperkeratosis, and brown onychodermal bands. Greenish-brown discoloration was noted on her right thumbnail and right index fingernail (Fig. 1a). There was no paronychia, toenail or joint involvement, hand dermatitis, or rashes elsewhere. A provisional diagnosis of nail psoriasis with secondary infection was made. Empirical topical clotrimazole and gentamicin were prescribed but stopped when cultures returned unyielding. Patch testing was also performed to exclude contact allergy-induced nail dystrophy, as the patient did not have a family history of psoriasis or other stigmata of psoriasis vulgaris. The onset of her nail changes also coincided with her regular application of nail polish for work purposes.
Patch testing was performed with the standard, cosmetic, and nail acrylate series (Chemotechnique Diagnostics, Vellinge, Sweden). Patch tests were applied with IQ Ultra chambers (Chemotechnique Diagnostics, Vellinge, Sweden) with an occlusion time of 48 hours. At the 72-hour reading, using the International Contact Dermatitis Research Group criteria, the patient demonstrated strong positive reactions (++) to 2-hydroxyethyl methacrylate 2.0% pet, hydroxypropyl methacrylate 2.0% pet, ethylene glycol dimethacrylate 2.0% pet, and 2-hydroxyethyl acrylate 0.1% pet (Fig. 1c).
The patient was treated with topical combination betamethasone dipropionate and calcipotriol gel and advised to avoid acrylate-containing nail cosmetics. On review 6 months later, her fingernail changes had fully resolved (Fig. 1b).
Acrylate compounds are incorporated into nail cosmetics due to their durability as polymers.1,2 Liquid acrylate monomers are applied onto nails before curing under ultraviolet light to become inert polymers.1,2 However, the curing process can be incomplete, leaving residual monomers as strong sensitizers with resultant allergic contact dermatitis.1-3
Allergens frequently involve 2-hydroxyethyl methacrylate, hydroxypropyl methacrylate, and ethylene glycol dimethacrylate, as seen in our patient. 1 Cross-reactivity of acrylic monomers is well documented.1,2
Common symptoms include paronychia, hand dermatitis, and facial dermatitis with aerosolization or secondary transfer.1,2 Patients themselves are often unaware of this sensitization source and continue nail polish application to cover up their nails, exacerbating the condition. 3
Isolated nail dystrophy is unusual and has only been reported in case reports.3,4 This can be misdiagnosed as onychomycosis or isolated nail psoriasis, especially in the absence of hand dermatitis.3,4 Differentiating this from psoriatic nails involves careful history taking and looking for the presence of psoriatic rashes and specific nail psoriasis signs such as nail pits or oil spots.3-5 Nail bed biopsy can also be helpful, but the diagnosis may be clinched with a clinical history of nail cosmetic exposure and a positive patch test. 5
This case study contributes to the breadth of contact allergy presentations with acrylate nail cosmetic use. Clinicians should be aware that isolated nail dystrophy is a possible clinical presentation.