Recommendation to test limonene hydroperoxides 0·3% and linalool hydroperoxides 1·0% in the British baseline patch test series.

BACKGROUND: There is a significant rate of sensitization worldwide to the oxidized fragrance terpenes limonene and linalool. Patch testing to oxidized terpenes is not routinely carried out; the ideal patch test concentration is unknown. OBJECTIVES: To determine the best test concentrations for limonene and linalool hydroperoxides, added to the British baseline patch test series, to optimize detection of true allergy and to minimize irritant reactions. METHODS: During 2013-2014, 4563 consecutive patients in 12 U.K. centres were tested to hydroperoxides of limonene in petrolatum (pet.) 0·3%, 0·2% and 0·1%, and hydroperoxides of linalool 1·0%, 0·5% and 0·25% pet. Irritant reactions were recorded separately from doubtful reactions. Concomitant reactions to other fragrance markers and clinical relevance were documented. RESULTS: Limonene hydroperoxide 0·3% gave positive reactions in 241 (5·3%) patients, irritant reactions in 93 (2·0%) and doubtful reactions in 110 (2·4%). Linalool hydroperoxide 1·0% gave positive reactions in 352 (7·7%), irritant reactions in 178 (3·9%) and doubtful reactions in 132 (2·9%). A total of 119 patients with crescendo reactions to 0·3% limonene would have been missed if only tested with 0·1% and 131 patients with crescendo reactions to 1·0% linalool would have been missed if only tested with 0·25%. In almost two-thirds of patients with positive patch tests to limonene and linalool the reaction was clinically relevant. The majority of patients did not react to any fragrance marker in the baseline series. CONCLUSIONS: We recommend that limonene hydroperoxides be tested at 0·3% and linalool hydroperoxides at 1·0% in the British baseline patch test series.

Does dermatoneuro syndrome have a viral aetiology?

Scleromyxoedema is a rare disease characterized by a generalized papular and sclerodermoid cutaneous eruption. It is associated with fibroblast proliferation and mucin deposition in the dermis. Most patients have a monoclonal gammopathy, defined by the presence of IgG. Treatment of scleromyxoedema is challenging, but there is mounting evidence to support the use of intravenous immunoglobulin (IVIg). Individual reports of systemic complications have been described. Dermatoneuro syndrome (DNS) is a rare but sometimes fatal manifestation, which consists of a triad of fever, coma and seizures preceded by a flu-like illness. We describe a patient with scleromyxoedema who developed DNS. Our case highlights interesting findings suggesting that DNS may have a viral aetiology. In addition, this case demonstrates a favourable response of the cutaneous features of scleromyxoedema to IVIg.

Contact dermatitis to ophthalmic solutions.

Periorbital and eyelid dermatitis is a recalcitrant and often distressing condition. Allergic contact dermatitis to ophthalmic solutions is an important cause of periorbital and eyelid dermatitis. In this review article, we discuss the allergens involved, the difficulties in patch testing, and the recommended concentrations and vehicles for patch testing.