Widespread bullous fixed drug eruption

Metformin-Induced Generalized Bullous Fixed-Drug Eruption with a Positive Dechallenge-Rechallenge Test: A Case Report and Literature Review

Metformin is a commonly used medication in diabetic patients. It can cause different complications including cutaneous adverse reactions. Metformin-induced fixed-drug eruption (FDE) has been reported in limited cases. Due to the popularity of metformin, clinicians need to be aware of uncommon drug reactions for proper diagnosis and treatment. Herein, we report a 43-year-old man with generalized bullous lesions with a positive dechallenge-rechallenge test diagnosed as metformin-induced generalized bullous fixed-drug eruption. Metformin dosage was stopped and lesions were treated with topical clobetasol propionate and oral prednisolone and cyclosporine-A. After a 6-month follow-up, he was well without any relapsing episodes.

A Review of Fixed Drug Eruption with a Special Focus on Generalized Bullous Fixed Drug Eruption

Fixed drug eruption (FDE) is a cutaneous adverse drug reaction characterized by the onset of rash at a fixed location on the body each time a specific medication is ingested. With each recurrence, the eruption can involve additional sites. Lesions can have overlying vesicles and/or bullae, and when they cover a significant percentage of body surface area, the eruption is referred to as generalized bullous fixed drug eruption (GBFDE). Due to the widespread skin denudation that can be seen in this condition, GBFDE may be confused clinically with Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). While treatments described for GBFDE include supportive care, topical and/or systemic steroids, and, recently, cyclosporine, the mainstay of management involves identifying and discontinuing the causative drug. This review article will provide an overview of FDE with an emphasis on its generalized bullous variant.

Fixed Drug Eruptions: An Update, Emphasizing the Potentially Lethal Generalized Bullous Fixed Drug Eruption

A fixed drug eruption (FDE) is a relatively common reaction associated with more than 100 medications. It is defined as a same-site recurrence with exposure to a particular medication. The primary approach and treatment for all types of FDEs are to identify and remove the causative agent, often accomplished by a thorough history of medication and other chemical exposures, and possibly prior episodes. The most common category of FDE, localized FDE, whether bullous or non-bullous, is self-limited. Although one can confirm the causative agent using oral challenge testing, it is not recommended due to the risk of severe exacerbation or possible generalization; patch testing is now preferred. Bullous FDE may resemble erythema multiforme. Treatment of localized FDE includes medication removal, patient counseling, and symptomatic relief. Failure to remove the causative agent in localized FDE can lead to recurrence, which is associated with increased inflammation, hyperpigmentation, and risk of a potentially lethal generalized bullous FDE (GBFDE), which may resemble Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). Distinguishing GBFDE from SJS and TEN is salient and will be stressed: GBFDE has more rapid onset in 1-24 h rather than in weeks, less or no mucosal involvement, less or no systemic involvement, and a tendency for a more favorable prognosis; however, recent experience suggests it may be just as life-threatening. This review will provide a comprehensive update and approach to diagnosis and management.

NSAIDs hypersensitivity: questions not resolved

PURPOSE OF REVIEW

NSAIDs are the drugs most frequently involved in hypersensitivity reactions (HSR). These are frequently prescribed at all ages. HSR are of great concern and can affect people at any age. These drugs can induce reactions by stimulating the adaptive immune system (IgE or T cell), known as selective responders or more frequently by abnormalities in biochemical pathways related with prostaglandin metabolism. These are known as cross-intolerant. With some exceptions, skin testing and in-vitro studies are of little value in selective responders.

RECENT FINDINGS

In the last years, several classifications have been provided based on clinical symptoms, time interval between drug intake and appearance of symptoms, response to other nonchemically related NSAIDs and the underlying disease. Based on this classification, several well differentiated categories within each group of entities cross-intolerant and selective responders are now recognized. The most complex groups for evaluation are cross-intolerant in which three major groups exist: NSAIDs exacerbated respiratory disease, NSAIDs exacerbated cutaneous disease and NSAIDs-induced urticaria/angioedema in the absence of chronic spontaneous urticaria. Within the selective responders, there are two mechanisms involved: drug-specific IgE or T-cell effector responses. New entities have been added to this classification like mixed reactions within the cross-intolerant category, that must manifest as anaphylaxis and multiple immediate selective reactions.

SUMMARY

The precise evaluation of patients with NSAIDs hypersensitivity following established guidelines will improve not only our understanding but also the management of these entities. As the number of patients affected with NSAIDs is important, further studies are warranted.

Bullous Fixed Drug Eruption Following Ibuprofen Ingestion

Fixed drug eruption (FDE) is a drug reaction involving skin and less commonly mucosal membranes. The common manifestation is localized well-demarcated patches or plaques appeared following receiving of a culprit drug. When re-exposure occurs, the rashes will appear at areas involved in previous episodes. Limited reports on bullous FDE due to ibuprofen have been documented before. Herein, we described an elderly man who experienced multifocal lesions in his oral mucosa, penis, and multiple sites of skin following ibuprofen ingestion confirmed as FDE by pathological studies. The culprit drug had been discontinued. Systemic and topical glucocorticoids as well as supportive care had been instituted. The patient's outcome was favorable and his lesions had been recovered within the next weeks. Patient's follow-up showed that he had received ibuprofen again sometime later resulting in anal mucosal lesion and similar penile involvement. In routine clinical practice, mucocutaneous adverse drug reactions should be considered. A high index of suspicion, the detailed medication history, the course of the symptoms, and distributing pattern of the lesions are essential clues for the diagnosis. However, judicious and prompt pathological studies can help to differentiate multifocal bullous FDE from major skin drug reactions such as Stevens-Johnson syndrome/toxic epidermal necrolysis.