CUTANEOUS MANIFESTATIONS OF ADVERSE DRUG REACTIONS

Lichen planus-like drug eruptions due to β-blockers: a case report and literature review

Lichen planus-like drug eruptions (LDE) can appear similar or identical to idiopathic lichen planus. We present a 45-year-old man with a widespread, violaceous, papular, generalized exanthema with histologic features of a lichenoid reaction, which subsequently resolved with the cessation of labetatol. We found 29 cases of previously reported β-adrenoceptor antagonist (β-blocker)-associated LDE. This is a relatively rare complication that may present as classic lichenoid papules indistinguishable from lichen planus and has a predilection for the limbs, chest, back, and oral mucosa. Histologically, there is a lichenoid infiltrate often with eosinophils. LDE may be due to drug cross-reactivity or as a result of a suppressed skin adrenergic system. Multiple potential medications in case studies and the inability to differentiate LDE from idiopathic lichen planus in cross-sectional association studies make any conclusive analysis difficult.

Effects of glucocorticosteroids on the skin and eye

The dermatologic anachronistic adage, "If wet--dry it, if dry--wet it!" has bee perhaps justifiably replaced by "Call the dermatologist to prescribe a steroid!" To say this without knowledge of the contents of this article and more importantly, to accept such cliches, is a disservice to the patient and a litigious liability to the prescriber. Recognizing the risk/benefit ratio of the most commonly used anti-inflammatory agents is essential. All therapies are most effective when used for their specific diagnosis. This article attempts to provide an update on the geometrically progressing knowledge regarding the uses and misuses of GCSs for the eye and skin.

Hypersensitivity vasculitis with leukocytoclastic vasculitis secondary to infliximab

Infliximab is an antibody to tumor necrosis factor (TNF) that is used in the treatment of Crohn disease and rheumatoid arthritis. This medication neutralizes TNF-alpha by binding to TNF receptors and inhibiting further induction of proinflammatory cytokines. We describe a patient with Crohn disease who developed hypersensitivity vasculitis with biopsy-proven leukocytoclastic vasculitis 9 days after her initial dose of infliximab. To our knowledge, this is the first reported case of infliximab-induced hypersensitivity vasculitis with leukocytoclastic vasculitis that occurred after the first dose of drug. It is important to note that hypersensitivity vasculitis can occur secondary to administration of this drug, even after the initial exposure.

Skin manifestations of drug reactions

Dermatologic manifestations of adverse drug reactions are commonly encountered in both hospital-based and ambulatory medical practice. Diagnosis is confounded by the myriad clinical presentations associated with cutaneous drug eruptions. Some presentations are highly characteristic, while others are not as straightforward, and may simulate other primary dermatoses. In many cases, patients are utilizing several medications and an obvious temporal relationship to a specific drug is not always apparent or expressed by the patient during disclosure of his or her medical history. A thorough medication history and a high index of suspicion are very important components in the diagnosis of drug eruptions.

Practical aspects of choosing an antibiotic for patients with a reported allergy to an antibiotic

Physicians often must select antibiotics for patients who are reported to have an antibiotic allergy. For penicillins, the sensitivity of penicillin skin testing for predicting serious allergic reactions is excellent. For other beta-lactam antibiotics, penicillin skin testing is useful for excluding the possibility of sensitivity to the beta-lactam ring. For other antibiotics, the patient history remains the most useful tool for determining whether a serious reaction is likely to occur with further drug exposure. The cross-reactivity between penicillins and second- or third-generation cephalosporins (excluding cefamandole) is probably no higher than is the cross-reactivity between penicillins and other classes of antibiotics. When a patient has a suspected immunoglobulin E-mediated antibiotic allergy, desensitization therapy should be considered, if the efficacy of alternate antibiotics is in doubt. For the treatment of serious infections, it is usually possible to safely administer the antibiotic of choice despite a history of possible antibiotic allergy.

Nonpigmenting solitary fixed drug eruption after skin testing and intra-articular injection of triamcinolone acetonide

BACKGROUND

Although several medications have been reported to cause fixed drug eruption (FDE) reactions, triamcinolone acetonide has not been previously described as an offending agent.

OBJECTIVE

To emphasize both an unprecedented causative agent and the extraordinary development of a FDE, we describe this response in a 42-year-old female patient.

METHODS

Because her history included a questionable reaction to corticosteroid preparations, prick and intradermal testing with triamcinolone acetonide was done to determine whether she could safely receive a triamcinolone acetonide injection.

RESULTS

Both skin test procedures and the intra-articular administration of triamcinolone acetonide caused FDEs on her right retroauricular area.

CONCLUSIONS

Because any drug may induce a FDE by any administration route, physicians should be aware of this delayed skin reaction when skin testing drugs.

Drug allergy diagnosis in humans: possibilities and pitfalls

Due to the potential hazards of drug allergies, an early and reliable diagnosis is crucial. The use of in vivo tests is not recent but, because of the hazards of skin testing in patients with a history of anaphylaxis, they had been abandoned for a while. Recent reevaluations have shown that for some drugs, e.g. antibiotics-reliable skin tests can ensure the diagnosis of drug allergy in up to 70% of cases. Many in vitro tests based on well-defined mechanisms, e.g. the basophil degranulation test have been used for the diagnosis of totally unrelated allergic mechanisms. It is almost impossible to interpret their validity as diagnosis tools. Nevertheless, other tests, e.g. the lymphocyte transformation test which have been evaluated in well-conducted recent studies, seem to have a good predictive value. Their use is still restricted to clinical trials or research studies. A reliable clinical approach as well as a detailed examination of the drug intake remains obligatory to diagnose drug allergy. Available in vivo and in vitro tests are sometimes used to confirm the diagnosis. The sensitivity and specificity of these tests is evaluated in clinical studies. Research to improve the existing tests and to develop new diagnostic tools is still of paramount importance.