Patch cross reactions

A 27-year-old woman, a pharmacist, had dermatitis on three separate occasions a few hours after she started to take oral deflazacort 6 mg for vesicular hand eczema (185). On each occasion, her symptoms included a widespread macular rash mainly on the inner aspects of her arms and legs and buttocks. She also had severe scaling, fever, nausea, vomiting, malaise, and hypotension. A skin biopsy was consistent with erythema multiforme, and direct immunofluorescence showed granular deposits at the dermoepidermal junction. Patch tests to the commercial formulation of deflazacort 6 mg (1% aqueous solution) and to pure deflazacort (1% aqueous solution) were positive, but there were no cross-reactions to other glucocorticoids. 

Local problems can occur, including hypersensitivity reactions (1). In one case of contact allergy, patch-testing was positive with clotrimazole (5% in petroleum), itraconazole (1% in ether), and croconazole (1% in ether) (7). The authors reviewed the possible cross-reactions between the subgroups of imidazoles. 

Thiomersal included in patch-test series has given varying frequencies of positive reactions. Cross-reactions occur to a few organic mercurials, but not to inorganic or metallic mercury. The allergic determinant seems to be the ethyl mercury radical in thiomersal. 

Patch testing in some human case studies show some cross-reactivity between various dithiocarbamate compounds and other chemically-similar compounds. Burry et al. (1976) reported cross reactions between Mankobunt (active ingredient mancozeb) and Zineb 65 (active ingredient polymeric zinc ethylene... 

Allergic contact dermatitis from tansy has been reported. Patch testing has indicated cross-reactions to a number of sesquiterpene lactone-containing plants in the Asteraceae family including tansy, dandelion, feverfew, and yarrow. The dermatitis is generally attributed to the sesquiterpene lactone compounds in tansy (Guin and Skidmore 1987 Hausen 1996 Hausen and Osmundsen 1983 Killoran et al. 2007 Mark et al. 1999 Paulsen et al. 1993, 2001). 

Mafenide (sulfamylon), as hydrochloride and acetate is extensively used in treatment of bums, and has significantly lowered the mortality from bum wound sepsis (YAFEE and Dressler 1969). It was found to be a common sensitizer in studies performed in Munich, outnumbered only by benzocaine in the years from 1960 to 1965 (Bandmann 1966). Mafenide acetate must not be used in patch testing, because patients sensitized to mafenide hydrochloride do not react to mafenide acetate (ScHREUS 1950). Cross-reactions to other related esters ofp-aminobenzoic acid occur relatively often (Bandmann 1967 Schulz 1962). Sulfonamides do not cross react with mafenide. Bandmann and Breit (1973) have reviewed the mafenide story. 

Kemekamp ASVW, van Ketel WG (1980) Persistence of patch test reactions to clioquinol (Vioform ) and cross-sensitization. Contact Dermatitis 6 455-460 Klaschka F, Beiersdorf HU (1965) Crux medicorum Allergie gegen nichtdeklarierte Salben-konservantien. MMW 107 185-188... 

Positive patch tests to phenolphthalein have been reported in some eczematous lesions (Bernstein 1931 Wise and Sulzberger 1933). False positive patch tests, reflecting epidermal hysteresis, have also been demonstrated after phenolphthalein administration (Shelley et al. 1972). Wyatt et al. (1972) found that serum taken during exacerbations produced a local inflammation when injected intradermally. Possible cross-reaction with erythrosin which is used as a food and drug colorant has been reported (Wile 1936). Other rare allergic manifestations after phenolphthalein administration are urticaria, Stevens-Johnson syndrome, lupus erythe-matosus-like eruptions, and encephalitis (Lindemayr 1959 Kendall 1954). 

In concentrations of o.i-o.2%, sodium benzoate is capable of producing immediate non-immunological (airborne) contact reactions (Lahti 1980 Nethercott and Lawrence 1984). Contact allergy has also been reported (Meynadier et al. 1982). The patch-test concentration is 5% pet. Allergic reactions are uncommon. Cross-reactions with benzoic acid are mentioned. 

Undecylenic acid is known as an antimycotic agent. Cross-reactions were reported to occur with zinc undecylenate (another antimycotic drug) (Gelfarb and Leiden i960). Patch-test concentrations are 2-5% pet. Allergic reactions are considered rare. 

Usnic acid is found in oak moss and used in perfumes. Usnea barbata is a lichen species that occurs in oak moss. Cross-reactions between structurally related lichen compounds are unclear, but must be considered (Mitchell 1965 Hausen et al. 1993). Contact dermatitis in vaginal ovules and contact allergy in deodorant spray has been reported (Hein and Tarnick 1987 Rafanelli et al. 1995). The patch-test concentration is 0.1% pet. Allergic reactions are rare or uncommon. 

Diazolidinylurea (Germall II). This is used widely as a preservative in liquid soaps, and is often combined with parabens (or other antifungal formulations). Allergic reactions occur - especially when stay-on products are used. Cross-reactions to and from imidazolidinyl urea occur (Ford and Beck 1986). Patch-test concentrations are 2% aqua or 2% pet. Allergic reactions are uncommon. 

Imidazolidinyl urea (115). This releases relatively small amounts of formaldehyde. Cross-reactions to and from diazolidinyl urea occur. Patch-test concentrations are 1% aqua or 1% pet (Ford and Beck 1986 Hectorne and Fransway 1994). 

Cidex is 2% acidic glutaraldehyde, a stable solution, but when activated (by means of buffering the solution with sodium bicarbonate to a pH of 7.5-8.0), it has a relatively strong irritant effect on the skin. When used as a hospital disinfectant, it is considered an occupational hazard (Hasen 1983). The patch-test concentration is 1% pet. Allergic reactions are uncommon (Nethercott et al. 1988). Cross-reaction with formaldehyde is possible. 

Phenol in a 1% ethanol solution can produce a delayed-type (slight) stinging which occurs minutes after application (Frosch 1995). Cross-reaction of phenol is possible with resorcinol, cresols and hydro-quinone. Patch test concentrations are 0.5-1% aqua. Allergic reactions are rare. Irritant patch-test reactions are frequent. 

Lysol. This is a compound of saponated cresol (mixture of 0-, m- and p-cresol) solution, usually 50% in saponified linseed oil), and was once used extensively as a disinfectant for floors and operating theaters in hospitals, p-chloro-m-cresol is the suspected allergen. It is reported to produce immediate immunological contact reactions (Sing-gih et al. 1986 Kiec-Swierczynska 1995). The patch-test concentration is 1% pet. Allergic reactions are not uncommon. Cross-reactions between p-chloro-m-cresol and p-chloro-m-xylenol (chloroxylenol) are common. 

Tribromsalan (TBS, halogenated salicylanilide, Temasept IV, Tuasol Hostynek 1989, CAS no. 87-10-5). This is an antiseptic that is now prohibited in the EC. Photoallergic and phototoxic reactions were reported (Miyauchi and Horio 1992). Cross reaction occurs with other halogenated salicylanilides. The patch-test concentration is 1% pet (Osmundsen 1970). 

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