Recommendation to include hydroxyethyl (meth)acrylate in the British baseline patch test series.

BACKGROUND: (Meth)acrylates are potent sensitizers and a common cause of allergic contact dermatitis (ACD). The frequency of (meth)acrylate ACD has increased with soaring demand for acrylic nails. A preliminary audit has suggested a significant rate of positive patch tests to (meth)acrylates using aimed testing in patients providing a clear history of exposure. To date, (meth)acrylates have not been routinely tested in the baseline patch test series in the U.K. and Europe. OBJECTIVES: To determine whether inclusion of 2-hydroxyethyl methacrylate (2-HEMA) 2% in petrolatum (pet.) in the baseline series detects cases of treatable (meth)acrylate ACD. METHODS: During 2016-2017, 15 U.K. dermatology centres included 2-HEMA in the extended baseline patch test series. Patients with a history of (meth)acrylate exposure, or who tested positive to 2-HEMA, were selectively tested with a short series of eight (meth)acrylate allergens. RESULTS: In total 5920 patients were consecutively patch tested with the baseline series, of whom 669 were also tested with the (meth)acrylate series. Overall, 102 of 5920 (1·7%) tested positive to 2-HEMA and 140 (2·4%) to at least one (meth)acrylate. Had 2-HEMA been excluded from the baseline series, (meth)acrylate allergy would have been missed in 36 of 5920 (0·6% of all patients). The top (meth)acrylates eliciting a positive reaction were 2-HEMA (n = 102, 1·7%), 2-hydroxypropyl methacrylate (n = 61, 1·0%) and 2-hydroxyethyl acrylate (n = 57, 1·0%). CONCLUSIONS: We recommend that 2-HEMA 2% pet. be added to the British baseline patch test series. We also suggest a standardized short (meth)acrylate series, which is likely to detect most cases of (meth)acrylate allergy.

A clinical assessment of a patch test kit marketed to U.K. hairdressers for detecting hair dye allergy.

BACKGROUND: In 2004 a U.K.-based company developed and marketed a patch test kit (Colourstart); Trichocare, Ridgmont, Beds, U.K.) for use by hairdressers. It is intended to assess whether clients have a 'problem with hair dye' and promotes itself as the 'only practical solution to sensitivity testing'. However, a patient presented with a hair dye reaction that had not been detected while using this patch test system. OBJECTIVES: To assess the Colourstart system in the next seven consecutive patients presenting with a history of adverse reactions to hair dyes. METHODS: The Colourstart system was tested in parallel with commercially available hair dye patch test reagents, where applicable. RESULTS: Only three of seven patients allergic to p-phenylenediamine were detected using this system and one patient allergic to toluene-2,5-diamine sulphate was not detected using this system. CONCLUSIONS: The results raise concerns about the sensitivity of this kit for consumer protection, but also wider questions about the regulation, use and interpretation of 'home diagnostic patch test kits' in general.

Photopatch testing of 1155 patients: results of the U.K. multicentre photopatch study group.

BACKGROUND: Photoallergic contact dermatitis can be difficult to diagnose if not appropriately investigated. Currently, the most common U.K. photoallergens appear to be sunscreen chemicals. The investigation of choice is photopatch testing (PPT), which is probably underused. In part, this is due to differences in methodology and results interpretation. OBJECTIVES: To conduct PPT using a group of sunscreen chemicals, defined indications and a standardized methodology including interpretation and relevance of reactions in patients attending for investigation at 17 centres across the U.K., Ireland and the Netherlands. METHODS: Patients (n = 1155) who fulfilled the inclusion criteria were investigated with PPT using sunscreen chemicals in addition to suspected topical products. Readings were taken at 24, 48 and 72 h following standardized ultraviolet A irradiation (5 J cm(-2)). The clinical relevance of any reaction was recorded. RESULTS: Of the 1155, 130 had allergic reactions (11.3%). Of these, 51 had photoallergy (PA) (4.4%), 64 had contact allergy (CA) (5.5%), and 15 patients had combined PA and CA (1.3%). Multiple PA was seen in some. The most common photoallergen was benzophenone-3 (27 reactions; 21%). Most reactions (60%) were clinically relevant. The most common indication for testing in patients found to have PA was a history of reacting to a sunscreen (41%). The other 59% had an exposed-site dermatitis/skin problem or a photodermatosis. Some centres (n = 8) performed readings after the standard 48-h reading, and an extra 32 PA and 22 CA reactions were detected, which were not evident at 48 h. A new photoallergen (octyl triazone) was detected in two patients. CONCLUSIONS: Sunscreen PA and CA are probably equally uncommon. Most reactions, of both reaction types, were relevant clinically. A large proportion of patients (59%) found to have PA was unaware of reacting to a sunscreen chemical, suggesting that PA should be considered as an explanation in any exposed-site dermatitis. Although this study focused on reactions at 48 h postirradiation, readings performed up to 96 h, while inconvenient, add value by detecting additional relevant responses. A previously unknown photoallergen was found, highlighting the need for awareness of novel photoallergens in the marketplace. A standardized PPT method not only encourages more use of this investigation, but also facilitates comparison of results between centres and so will improve our understanding of PA.

Changing patterns of contact allergy in chronic inflammatory ear disease.

Chronic inflammatory ear disease comprises a wide range of conditions. Although contact allergy to topical medicaments is common in such conditions, the causes of these reactions have not been examined in a large series for over a decade. Our aim was to investigate the major sensitizers recorded in 179 patients over the last 17 years. Medicament contact allergic dermatitis was diagnosed in 45 patients (25%), of whom 34 (76%) demonstrated a relevant allergy to neomycin, 28 (62%) to framycetin, 11 (31%) to gentamicin, 8 (18%) to quinoline mix and 5 (11%) to caine mix. Of all neomycin-allergic patients, 28 (76%) were also allergic to framycetin and 12 (43%) to gentamicin. Comparing the first 60 patients (1985-94) to the most recent 60 (1998-2002) identified a significant recent reduction in the number of patients allergic to neomycin (P = 0.002) and framycetin (P = 0.050), with a non-significant reduction in the total number diagnosed as medicament-allergic (P = 0.066). We have therefore demonstrated a high frequency of medicament contact allergy in chronic inflammatory ear disease, supporting the routine use of patch testing in these patients. We have also shown a significant recent reduction in the number of such patients with allergy to neomycin and framycetin.

Cytomegalovirus-associated gastric ulcer in an immunosuppressed patient with pemphigus vulgaris.

A 79-year-old female with pemphigus vulgaris developed a cytomegalovirus (CMV)-associated gastric ulcer whilst on standard immunosupression with azathioprine and prednisolone. Following treatment with ganciclovir and ranitidine the ulcer healed. CMV infection frequently involves the gastrointestinal tract of immunocompromised patients causing inflammation, ulceration and haemorrhage. Although it has also been described in patients treated with immunosuppressive therapy for malignancy and other autoimmune disease, we are not aware of previous reports in patients treated for autoimmune bullous disease.

Avian mite dermatitis.

Avian mite infestation is a rare cause of pruritic dermatoses in humans. The mites spend the majority of their life cycle on the avian host but may be transmitted to man as a result of direct contact and also through airborne spread. We describe a case of infestation with the Northern Fowl Mite (Ornithonyssus sylviarum) from an abandoned birds nest in the roof of a patients home. This caused a pruritic erythematous papular eruption on exposed sites that settled with topical steroids. We discuss the diagnosis and range of clinical manifestations produced by avian mites.

Renal angiogram abnormalities in a case of cutaneous polyarteritis nodosa.

The existence of a limited cutaneous form of polyarteritis nodosa remains controversial. It has been characterized and contrasted with systemic polyarteritis nodosa by running a chronic course and having a relatively good long-term prognosis. We report a case with clinical features fitting the criteria for cutaneous polyarteritis nodosa but also showing evidence of associated renal aneurysms on selective visceral angiography. These findings suggest that the differentiation between systemic and cutaneous forms might be an oversimplification and we discuss the relationship between the two forms.

Amoxycillin-induced flexural exanthem.

We describe a 37-year-old man who developed an acute, inflammatory flexural eruption shortly after taking amoxycillin, then erythema multiforme-like lesions on the palms and soles. The eruption resolved with systemic corticosteroids, and positive patch tests with amoxycillin supported a drug-induced aetiology. A few similar cases have been described as the 'baboon syndrome' or intertriginous drug eruptions. We draw attention to this rare, distinctive drug eruption.