Cross-reactions patch testing

Numerous positive delayed skin tests in patients with contrast medium-induced non-immediate skin reactions have been reported when the patients were tested with the culprit contrast medium [summarized in 1]. In a large European multicenter study, 37% of patients with non-immediate reactions were positive in delayed IDEs and/or patch tests [13]. The majority of the patients also reacted to the culprit contrast medium and also to other, structurally similar RCM. Notably, in more than 30% of those skin test-positive patients a RCM had been administered for the first time. Thus, there is a lack of a sensitization phase. Again it may be hypothesized that these previously non-exposed patients may have already been sensitized. Different patterns of RCM cross-reactivity indicate that several chemical entities could be involved. No positive skin tests have been obtained with other contrast medium excipients, such as ethylenediaminetetraacetic acid (EDTA), and only rarely patients have been found to react to inorganic iodide. 

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. 

Systemic contact dermatitis is a delayed hypersensitivity skin reaction that results from systemic exposure. Exanthematous systemic contact dermatitis from ethylenediamine has been reported with aminophylline. Disodium edetate (ethylenediamine tetra-acetic acid) has caused contact dermatitis after local application (SEDA-23, 242), and ethylenediamine cross-reacted in a patch test in a patient who had had contact dermatitis with hydroxyzine, an ethylenediamine derivative (SEDA-22, 178). Prior sensitization can occur to ethylenediamine in creams and ointments (SED-14, 485). 

A 71-year-old Japanese man developed an itchy erythematous papular eruption after using an over-the-counter medicament for skin wounds (Makiron) for 1 month (34). Patch tests with the constituents showed positive reactions to dl-chlorphenamine maleate and cinchocaine hydrochloride (both 1% in petrolatum). Patch tests with lidocaine hydrochloride and mepivacaine hydrochloride showed no cross-sensitization. 

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. 

Sensitization reactions may follow the prolonged application of strong solutions to the skin, although patch tests have shown that chlorocresol is not a primary irritant at concentrations up to 0.2%. Cross sensitization with the related preservative chloroxylenol has also been reported. " "" At concentrations of 0.005% w/v, chlorocresol has been shown to produce a reversible reduction in the ciliary movement of human nasal epithelial cells in vitro and at concentrations of 0.1% chlorocresol produces irreversible ciliostasis therefore it should be used with caution in nasal preparations. " However, a clinical study in asthma patients challenged with chlorocresol or saline concluded that preservative might be used safely in nebulizer solution. ... 

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). 

These local anesthetics, including lidocaine (Xylocaine), mepivacaine (Carbo-caine), Prilocaine (Citanest), and bupivacaine (Marcaine) are weak sensitizers, but allergic reactions are sporadically reported, e. g., lidocaine (Turner 1977). Recently Fregert et al. (1979) described two patients developing lidocaine allergy after 8 and 1 month use of Xyloproct ointment (lidocaine 5%, hydrocortisone acetate) they also had positive patch tests to related amide anesthetics, both to mepivacaine, one to bupivacaine and prilocaine. A positive reaction to the chemically unrelated cincaine was interpreted as concomitant sensitivity rather than cross-sensitivity. Safe substitutes for benzocaine-sensitive patients include lidocaine, mepivacaine, prilocaine, bupivacaine, and pyrocaine (Fisher 1973 p. 312), all based on an amide structure. Lidocaine-sensitive patients may use tetracaine (pontocaine), a derivative of aminobenzoic acid. 

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 patients sensitive to p-phenylenediamine, the intake of certain azo dyes caused a flare of their dermatitis (Baer and Leider 1949 Sidi and Arouete 1959). The cross-reactivity between various allergenic dyes has been tested by Weirich (1961). Contact dermatitis to azo dyes employed in the textile and leather industries was described by Sultrmond et al. (1967). Roeleveld and van Ketel (1976) reported a patient with a dermatitis caused by a yellow shirt. The patch test was positive to the azo dye, tartrazine. Interestingly the eruptions worsened after drinking orange juice which could have contained tartrazine. Calnan (1976) found positive patch tests to quinazoline yellow which is used in foods, drugs, and cosmetics. Grater (1976) reported 133 positive reactions to a set of such dyes. 

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. 

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