Conjunctival allergic contact hypersensitivity

Abuse of vasoconstrictive eyedrops mimicking an ocular pemphigoid

PURPOSE

To describe conjunctival histopathologic alterations induced by excessive chronic astringent use.

METHODS

Report of a case with clinical picture, epicutane test results, histologic workup of conjunctival biopsy using conventional staining, and immunohistochemical markers.

RESULTS

A 45-year-old man using a phenylephrine preparation hourly for years presented with grotesque eye redness, fornix shortening, and scarring of puncta lacrimalia. Direct and indirect immunofluorescence were negative for ocular pemphigoid. Histology revealed signs of chronic inflammation and neovascularization in the conjunctiva. Symptoms resolved after cessation of therapy.

CONCLUSIONS

Chronic abuse of decongestant eyedrops can produce a clinical picture resembling an ocular pemphigoid. Histology suggests that late onset immunoreaction and chronic vasoconstriction cause chronic inflammation and neovascularization, respectively.

Anaesthetists should be aware of delayed hypersensitivity to phenylephrine

Delayed reactions to phenylephrine, used as a mydriatic agent during ophthalmological surgical procedures, are well known. We diagnosed a delayed hypersensitivity reaction to phenylephrine included in an ophthalmic insert in a woman presenting, 24 h after surgery, with an acute blepharoconjunctivitis associated with eyelid eczema of the operated eye. The diagnosis was supported by the recognition of clinical symptoms associated with a positive patch test to phenylephrine. Patients who present with previous contact eczema to phenylephrine may develop a generalized eczema if phenylephrine is injected intravenously. Intravenous phenylephrine is increasingly being used in the operating room to treat hypotension. This case report confirms the need for systematic allergological investigation of all drugs and substances administered during the peri-operative period in order to avoid a delayed hypersensitivity reaction occurring after the peri-operative period. Anaesthetists should be aware of the possibility of delayed hypersensitivity reactions involving phenylephrine.

Sympathomimetic drug allergy: cross-reactivity study by patch test

INTRODUCTION

Sympathomimetic (alpha-adrenergic) drugs are mainly used because of their vasoconstrictor properties, for nasal congestion, or as mydriatics. Although sympathomimetic drugs are used often, allergic reactions are rare, especially when the drugs are administered systemically. Cross-reactivity may exist among catecholamine derivatives, although reported data on this are contradictory. In this study, we investigate if there is cross-reactivity in patch tests among these drugs.

MATERIAL AND METHODS

Patch tests with 10% phenylephrine and 10% pseudoephedrine in petrolatum, and 10% and 20% ephedrine, 10% phenylpropanolamine, 5% fepradinol, 1% methoxamine, and 10% oxymetazoline, all administered in dimethyl sulfoxide (DMSO), were carried out in 14 patients with a history of allergy to any of these drugs. DMSO was used as the negative control.

RESULTS

All patients except one (patient number five) showed positive patch-test reactions to at least two different drugs. Nine patients (64.3%) were cross-sensitized to three or more different drugs, and 57.1% of patients were sensitized to four or more sympathomimetic drugs. Patients who experienced generalized rashes caused by orally administered pseudoephedrine had a stronger response and more cross-reactivity with other sympathomimetic drugs in patch tests than those who experienced local contact dermatitis.

CONCLUSIONS

We conclude that there is cross-reactivity among the different sympathomimetic drugs tested, especially if the drug is administered systemically.

Erythrodermia to pseudoephedrine in a patient with contact allergy to phenylephrine

BACKGROUND

Phenylephrine and pseudoephedrine are sympathomimetic drugs belonging to the phenylamine family. Adverse cutaneous effects associated with these drugs have been reported but, in view of their frequent use, appear to be rare. The very close chemical structures of these drugs could explain potential cross-reactions among them but the results reported in the literature are controversial.

CASE REPORT

An 18-year-old woman developed blepharoconjunctivitis after application of phenylephrine and tropicamide eye drops. Four years after this reaction, she took 1 tablet of Narine (pseudoephedrine and loratadine) and 3-4 hours later developed a generalized erythrodermic reaction. Cutaneous biopsy revealed hydropic changes in the basal layer and, in the dermis, moderate edema with slight perivascular lymphocyte and eosinophil infiltrates. Patch tests with European standard series, commercial eye drops, tropicamide, phenylephrine, pseudoephedrine and other sympathomimetic agents were applied to the patient's back. After 47 and 96 hours, only the patches with pseudoephedrine and phenylephrine were positive.

CONCLUSIONS

We believe that our patient has presented two different reactions with different clinical outcome and histopathology, which are unlikely to be due to cross-reactivity between the drugs involved. We have found no similar coincidences reported int the literature.