Systemic contact dermatitis from pseudoephedrine

A patient with rhinitis developed systemic contact dermatitis when starting oral treatment with Rhinalair, containing pseudoephedrine hydrochloride. A few months later, another oral treatment Rinutan, containing norephedrine hydrochloride, provoked a more severe generalized eczema. Patch test reactions were strongly positive to ephedrine and pseudoephedrine, slightly positive to phenylephrine and negative to epinephrine. Norephedrine was not tested.     

Allergic contact eczema to phenylephrine

A female patient developed periorbital eczema and conjunctivitis prior to cataract surgery. Investigations revealed an allergic contact eczema to phenylephrine hydrochloride 10% eyedrops being used pre-operatively for mydriasis.     

Probable irritant contact dermatitis from phenylephrine in eyedrops with irritant (false-positive) phenylephrine patch test reactions

A 61-year-old white woman developed an acute eczema of the eyelids and periorbital region after application of eyedrops containing 10% phenylephrine hydrochloride (HCI) for an ophthalmologic examination. The patient showed false-positive (irritant) reactions both to eyedrops as is and phenylephrine HCI 10% aqueous after 48 hours, quickly fading at 72 hours, and unremarkable at 96 hours. There were false-positive results in 2 of 19 controls. Patch testing with phenylephrine HCI 1% aqueous, which is the correct testing concentration, was negative in both case patients and controls. Open tests showed a soaplike irritant effect only to 10% aqueous phenylephrine after 48 hours sharply marginated to the test site area. Repeated open application test further confirmed the above findings. Intradermal testing with phenylephrine showed no delayed reactions either in the affected patient or 19 controls. Irritant patch testing reactions do not necessarily indicate a diagnosis of irritant contact dermatitis; however, it is likely that in our patient, phenylephrine at its higher concentration (10%) was responsible for the clinical picture of irritant dermatitis.     

Contact allergy to ophthalmic dipivalyl epinephrine hydrochloride: demonstration by patch testing

A patient presented with a 3-month history of conjunctivitis and periocular eczema. He had a 3-year history of glaucoma and was being treated with 3 different locally applied eyedrops (Timoptic (timolol maleate) ophthalmic solution 0.25%, Pilocar (pilocarpine) ophthalmic solution 1%. and Propine (dipivalyl epinephrine hydrochloride) ophthalmic solution 0.1%). Patch testing with all 3 undiluted eyedrop solutions revealed a reaction only to Propine eyedrops. Patch testing to the individual components of Propine eyedrops revealed an allergic reaction to 0.5%, dipivalyl epinephrine hydrochloride that was apparent on the 2nd patch test reading. After discontinuing the Propine eyedrops, the conjunctivitis as well as the periocular dermatitis resolved, proving that the positive patch tests were relevant to both. It was reported that re-exposure to dipivalyl epinephrine hydrochloride by intra-ocular challenge was necessary to diagnose this allergy. This is the first demonstration of dipivalyl epinephrine hydrochloride allergy by patch testing. Since the 1st patch test reading (2 days) was weak. 2nd patch test (4 days) readings may be important in diagnosing this allergy by patch testing.     

Reliability of diagnostic tests for contact allergy to mydriatic eyedrops

Adverse reactions due to the administration of mydriatic eyedrops are not uncommon. In Spain, the most commonly used are phenylephrine, tropicamide and cyclopentolate hydrochloride. In this study, 37 patients with adverse reactions to the administration of mydriatic eyedrops were investigated from January 1993 to June 1997. The aim was to assess the reliability of the diagnostic methods used, particularly the adequate concentration of allergens and the introduction of conjunctival challenge as a safe and accurate diagnostic tool in those patients who could not be diagnosed by other methods. Phenylephrine was the drug most frequently causing sensitization (93.5%) among the 31 allergic patients. Preservatives were the cause in only 1. Patch testing detected allergy in 68.5% of the subjects. 2 concentrations (1% and 10%) and vehicles (pet. and aq.) were used for phenylephrine. The most reliable was 10% aq. Reading at D4 was more useful than at D2. The sensitivity of the patch test was low (72.4%) and its negative predictive value (NPV) poor (42%). In 24%o f patients, allergy to phenylephrine was detected only by conjunctival challenge test. This diagnostic method is safe and helpful and has not previously been used to diagnose adverse reactions due to mydriatic eyedrops.     

Allergic contact sensitivity to mydriatic agents on a nurse's fingers.

We report a case of contact sensitivity to a cycloplegic mydriatic agent (Mydrin-P) on the fingers of a nurse whose work included the instillation of eyedrops into patients undergoing routine funduscopic examination in a hospital ophthalmology department. The lesion showed well-demarcated brownish erythema with scaling on the second and third fingers of her left hand, which are used for opening the eyes of patients and are subjected routinely to contact with leaking mydriatic eyedrops. The results of a patch test to Mydrin-P and to its pharmacologic components tropicamide and phenylephrine hydrochloride were positive. These chemicals seem to be weak antigens since reports of allergic reactions to them are rare. This case exemplifies a unique occupational contact dermatitis.     

Allergic contact dermatitis due to phenylephrine hydrochloride, with an unusual patch test reaction

2-day (2-D) closed patch tests are often used in daily clinical practice and useful for evaluating the cause of allergic contact dermatitis. However, even when 2-D closed patch tests at appropriate concentrations are performed for suspected allergic contact dermatitis based on clinical findings, positive reactions are not always obtained. Therefore, although the use of the allergen again induces similar symptoms, a definite diagnosis cannot be made in some cases. We report a case of allergic contact dermatitis due to phenylephrine hydrochloride in eyedrops, with an unusual patch test reaction. Although the results of the routine 2-D closed patch test were negative, a definite diagnosis could be made by closed scratch-patch test. In addition, long-lasting allergic patch test reactions were observed at the positive scratch-patch test site for about 3 months. We speculated that these unusual results on patch testing in our case were associated with the degree of percutaneous absorption of causative agents. Therefore, even when 2-D closed patch tests are negative, scratch-patch tests may be indicated for patients in whom clinical symptoms continue strongly to suggest contact dermatitis.     

The CXCR3 activating chemokines IP-10, Mig, and IP-9 are expressed in allergic but not in irritant patch test reactions.

Differentiation between allergic and irritant contact dermatitis reactions is difficult, as both inflammatory diseases are clinically, histologically, and immunohistologically very similar. Previous studies in mice revealed that the chemokine IP-10 is exclusively expressed in allergic contact dermatitis reactions. In the present study, we investigated whether the mRNA expression of IP-10 and the related CXCR3 activating chemokines, Mig and IP-9 are also differentially expressed in human allergic contact dermatitis and irritant contact dermatitis reactions. Skin biopsies from allergic (13 cases) and sodium lauryl sulfate-induced irritant patch test reactions (13 cases), obtained 1-72 h after patch testing, were studied by means of an in situ hybridization technique. Results of chemokine mRNA expression were correlated with clinical scoring, histology, and immunohistochemical data including the proportion of inflammatory cells expressing CXCR3, the receptor for IP-10, Mig, and IP-9, and ICAM-1 and HLA-DR expression on keratinocytes. IP-10, Mig, and IP-9 mRNA were detected in seven of nine allergic contact dermatitis reactions after 24-72 h, but not in sodium lauryl sulfate-induced irritant contact dermatitis reactions. ICAM-1 expression by keratinocytes was only found in allergic contact dermatitis reactions and correlated with chemokine expression. Moreover, up to 50% of the infiltrating cells in allergic contact dermatitis expressed CXCR3, in contrast to only 20% in irritant contact dermatitis reactions. In conclusion, we have demonstrated differences in chemokine expression between allergic contact dermatitis and irritant contact dermatitis reactions, which might reflect different regulatory mechanisms operating in these diseases and may be an important clue for differentiation between allergic contact dermatitis and irritant contact dermatitis reactions.     

Allergic contact dermatitis due to hexamethylenetetramine in core molding

Hexamethylenetetramine is an odorless powder and slowly liberates formaldehyde in an acid medium or when heated. It is usually used in the manufacture of formaldehyde resins, rubber and the explosive, cyclonite. It is also used as a hardener in core molding processes. It was reported as one of the formaldehyde releasers and as a cause of formaldehyde contact dermatitis. We report an allergic contact dermatitis due to hexamethylenetetramine, with a positive patch test reaction to hexamethylenetetramine (1% pet.) but not to formaldehyde (2% aq.). We concluded that this case was an allergic contact dermatitis from hexamethylenetetramine itself.     

Skin acceptance of transcutaneous nitroglycerin patches: a prospective study of 33 patients

Transdermal nitroglycerin is commonly used and may induce contact dermatitis. The frequency of adverse skin reactions is controversial and may vary from 10% to 75%, according to various authors. 33 patients using transdermal nitroglycerin for more than 7 days were examined and patch tested (nitroglycerin 0.5% aq., 2% pet. and TTS in toto). 5 patients (15%) had adverse reactions. The patch tests were all negative in the 33 patients. Contact dermatitis occurs in many cases, about 15% of the cases with the newly available TTS, and even if patients respect the conditions for using TTS. These contact dermatitides are mainly irritant reactions and do not require transdermal nitroglycerin treatment to be stopped. Nevertheless, since some cases of allergic contact dermatitis have been reported, a contact dermatitis from transdermal nitroglycerin should lead to patch testing.     

Cross‐elicitation responses to 2‐methoxymethyl‐p‐phenylenediamine in p‐phenylenediamine‐allergic individuals: Results from open use testing and diagnostic patch testing

Background

Allergic contact dermatitis caused by p‐phenylenediamine (PPD) is a health concern for hair dye users. Because of its lower sensitization potency, the PPD derivative 2‐methoxymethyl‐p‐phenylenediamine (ME‐PPD) has been developed as an alternative hair dye for primary prevention. However, cross‐elicitation responses can occur in PPD‐allergic subjects.

Objectives

To compare cross‐elicitation responses to ME‐PPD in open use and diagnostic patch testing of PPD‐allergic subjects with hair dye‐related allergic contact dermatitis.

Methods

Reactions to ME‐PPD were investigated in 25 PPD‐allergic subjects by performing (1) 45‐minute open use testing with a hair dye containing 2.0% of either ME‐PPD or PPD, and (2) patch testing with increasing ME‐PPD concentrations (0.1%–2.0% pet.).

Results

Of the 25 PPD‐allergic subjects, 21 (84%) reacted to open use testing with a hair dye containing 2.0% PPD, and testing with 2.0% ME‐PPD led to cross‐elicitation in 12 (48%). When patch tested with increasing ME‐PPD concentrations, 13 (52%) cross‐reacted at 0.1% (lowest dose) and 21 (84%) at 2.0% (highest dose), indicating decreased reactivity as compared with published PPD dose‐response data.

Conclusion

In line with the decreased cross‐reactivity of ME‐PPD in hair dye open use testing, PPD‐allergic subjects show an attenuated cross‐elicitation dose response to ME‐PPD in patch testing.     

Nickel contact hypersensitivity in children

Nickel allergic contact dermatitis is the most prevalent allergy in North America, with an incidence of 14.3%. It is on the rise from 10 years ago, when the incidence was 10%. This has been presumed to represent an increased exposure to nickel in the environment-especially in costume jewelry and belt buckles. We examined a group of 30 pediatric patients who had either a personal history of umbilical or wrist dermatitis, or a family history of nickel allergic contact dermatitis. All of these patients had a positive patch test to nickel sulfate 5%. Moreover, 50% of patients had an id reaction; all of these patients had positive patch tests that were papular in nature, similar to their papular id reaction. We posit that the presence of a positive family history may be a positive predictor of nickel allergic contact dermatitis, requiring nickel avoidance, especially in atopic children. Based on the high level of positive reactions in patients with umbilical dermatitis and an id reaction, patch testing to nickel in these patients is most likely to yield a useful result. Knowledge of reactivity to nickel would then allow parents and patients to initiate nickel avoidance earlier in life.     

Contact allergy to cocamidopropyl betaine

Cocamidopropyl betaine is an amphoteric surfactant used increasingly in cosmetic products. We describe 20 cases of cosmetic allergy to cocamidopropyl betaine; all were caused by shampoo or shower gel. 8 patients were hairdressers, who had occupational allergic contact dermatitis from shampoos. We recommend patch testing cocamidopropyl betaine 1%. aq. routinely in hairdressers with dermatitis of the hands, and in all patients suspected of suffering from cosmetic allergy.     

Occupational allergic contact dermatitis to airborne nitrofurazone

Allergic contact dermatitis to nitrofurazone has been reported from Europe and elsewhere from the use of eyedrops and topical ointments, and the drug in some livestock feeds and veterinary medications has caused a few cases of allergic contact dermatitis in humans. The authors report what appears to be the first case of contact dermatitis from airborne nitrofurazone secondary to a powdered aquarium water additive.     

Allergic contact dermatitis from 1,6-diisocyanatohexane in an anti-pill finish

We report an outbreak of occupational allergic contact dermatitis from 1,6-diisocyanatohexane (old name hexamethylene diisocyanate or HDI), in the anti-pill finish Evafanol AS-1, in 2 clothing factories. The 19 operatives from 2 dressmaking mills all complained of work-related dermatitis. 5 of the subjects had positive patch tests to the fabric with which they were working, and when all 19 were patch tested to Evafanol AS-1 (1% aq.), 11 were positive. 6 of these 11 were patch tested to HDI (1% pet.) and all 6 were positive. It appears that HDI in our group of clothing workers acted as a potent sensitizer affecting around 10% of the workforce.     

Contact allergy to antihistamines is not common

Topical antihistamines are available as creams, lotions, eyedrops, nasal preparations, aerosols, and suppositories. Antihistamines (or H₁-receptor antagonists) have antipruritic properties, a mild local anesthetic effect and may also diminish capillary permeability. They can be classified into 6 groups by their chemical structure (1): alkylamines, ethanolamines, ethylenediamines, phenothiazines, piperazines, and other H1-receptor antagonists. Application to the skin is generally considered to carry an unacceptably high risk of sensitization (1, 2). Recently, several cases have been reported of allergic contact dermatitis from topically-applied doxepin hydrochloride, a tricyclic antidepressant that has very potent antihistaminic activity (3–5).     

Suppressed cell-mediated immunity associated with eczematous inflammation.

In order to determine if an eczematous inflammation could have any influence upon already established cell-mediated immune reactivity, a widespread allergic as well as primary irritant, eczematous dermatitis was produced in tuberculin-sensitive guinea pigs. Their tuberculin reactivity was significantly suppressed both by allergic contact dermatitis due to dinitrochlorobenzene and by primary irritant dermatitis due to croton oil. After the dermatitis had subsided, tuberculin reactivity was restored to approximately the same level as before the induction of the dermatitis, which suggests that the suppression is temporary.     

Allergic contact dermatitis to phenylephrine eye drops in an infant

Ophthalmic medications used for diagnostic or therapeutic purposes are common causes of allergic contact dermatitis around the eyes. We report a case of periocular allergic contact dermatitis due to tropicamide and phenylephrine eye drops in a 1‐year‐old infant.     

Patch testing with metalworking fluids from the patient's workplace

In view of the wide variety of components currently used in metalworking fluids (MWF), relevant contact sensitizations may be overlooked, because commercially available MWF test series cannot cover the full spectrum. Hence, patch testing with MWF from the patient's workplace is an important additional diagnostic tool. However, recommendations on how to perform such patch tests vary. We retrospectively analyzed patch test data of the Department of Dermatology in Dortmund, 1992-2003. In 141 metalworkers tested because of suspected occupational contact dermatitis due to MWF, 829 patch tests with 306 samples of MWF were performed. Water-based MWF (wb MWF) were mainly tested in 2 dilution series, i.e. pure (workplace concentration), 10% aq. and 1% aq., and pure, 50% aq. and 10% aq. Positive reactions to wb MWF occurred in 27 patients. Patch testing with wb MWF at workplace concentration resulted in 16.1% (39/242) positive reactions, with a positivity ratio of 69% and a reaction index of 0. From the analysis of reaction patterns and concomitant reactions, we conclude that most of these positive reactions indicated true contact allergy. With lower concentrations, relevant allergic reactions may be missed. Neat oils were tested as is or diluted from 1 to 50% in olive oil, but no reactions at all were observed. For optimum benefit of patch testing with MWF from the patient's workplace, breakdown testing is recommended. To overcome the time-consuming difficulties associated with this procedure, we propose a centre for information and documentation of contact allergies due to occupational exposure. Furthermore, full declaration of MWF ingredients is desirable.     

Occupational dermatitis in animal feed mill workers

In an epidemiological study of occupational dermatitis in 15 different northern Italian animal feed mills, 204 workers were interviewed, examined and patch tested to 34 allergens, selected from the additives most commonly used in the animal feed mills under consideration. The prevalence of occupational contact dermatitis was 13.7% (28/204): 7.8% (16/204) irritant contact dermatitis and 5.8% (12/204) allergic contact dermatitis from animal feed additives. Among the latter, there were sensitizations, to our knowledge hitherto unreported in the literature: to indigo carmine (2 cases), monensin sodium (1 case), thiabendazole (1 case), methylchlorpindol (1 case) and amprolium hydrochloride (1 case). 3.9% (8/204) of the workers complained only of pruritus sine materia on exposed areas of the body. Contact dermatitis increased with respect to duration of employment: the difference in the rate of contact dermatitis between workers employed in animal feed mill for greater than 10 years and those employed for less than 10 years was statistically significant (p less than 0.05). 6.8% (14/204) had latent sensitivity, which was more frequent in workers with less than 1 year of employment with respect to more experienced colleagues.