Concomitant allergic contact dermatitis from diphenhydramine and metronidazole

Metronidazole Induced Cutaneous Adverse Drug Reaction- A Systematic Review of Descriptive Studies

BACKGROUND

A substantial number of research studies on metronidazole-related cutaneous symptoms have recently been published. Our objective was to identify and evaluate descriptive studies that described metronidazole-related skin manifestations, therapeutic interventions, and consequences.

METHODS

A comprehensive literature search was carried out in the PubMed, Scopus, and grey literature databases from inception to April 2022 without any constraints, as well as a snowball search in Google and a search in Google Scholar. Descriptive articles describing metronidazole-related cutaneous manifestations were considered for the review. Two distinct reviewers carried out the research selection, data extraction, and quality assessment; any discrepancies were resolved by consensus with the third reviewer.

RESULTS

About 24 out of 4648 descriptive studies, including 26 patients (20 Female patients and 6 male patients), were included in this review. The included studies comprised a range of ages from 16 to 78 years old. Metronidazole was indicated for the treatment of bacterial vaginosis, trichomoniasis, sepsis, anti-infection therapy, perforated appendicitis, rosacea, vaginal discharge, dysentery, acne rosacea, trichomonal vaginitis, lichen planus, liver abscess, facial rosacea, intestinal amoebiasis, and gingivitis. Fixed drug eruption was the most common skin manifestation which was reported in 7 cases included in this review. Cutaneous manifestations were ameliorated by cessation of the offending drug and by apportioning antihistamines, topical steroids, parenteral corticosteroids, emollients, and topical moisturizers.

CONCLUSION

Clinicians and healthcare professionals should be cognizant of the potential cutaneous adverse drug reactions (CADRs) induced by metronidazole to mitigate fatal circumstances. The management of the CADRs appears to respond effectively with immediate drug discontinuation and supportive therapy.

Evaluation of Treatments for Pruritus in Epidermolysis Bullosa

Pruritus is a common complication in patients with epidermolysis bullosa (EB). There is limited published data about the treatments that individuals with EB use for pruritus. The objective of the current study was to determine quantitatively which treatments individuals with EB have used for pruritus and to evaluate the perceived effectiveness of these treatments in pruritus relief. A questionnaire was developed to evaluate the treatments and therapies used for pruritus in patients of all ages and for all types of EB. Questions about bathing products, moisturizers, topical products, oral medications, dressings, and alternative therapies were included. A 5-point Likert scale (-2 = relieves itch a lot, -1 = relieves itch a little, 0 = no change, 1 = increases itch a little, 2 = increases itch a lot) was used to evaluate perceived effectiveness. Patients from seven North American EB centers were invited to participate. Greasy ointments (53.4%), lotions (45.2%), creams (40.4%), and oral hydroxyzine (39.0%) were the most frequently used treatments for pruritus. Treatments that were used frequently and perceived to be the most effective included creams (mean = -1.1), topical prescription corticosteroids (mean = -1.0), oils (mean = -0.9), oral hydroxyzine (mean = -0.9), topical diphenhydramine (mean = -0.9), and vaporizing rub (menthol, camphor, eucalyptus) (mean = -0.9). Systemic opioids (mean = 0.3), adherent bandages (mean = 0.3), and bleach baths (mean = 0.2) slightly increased pruritus. Randomized controlled trials of therapies will be necessary to develop evidence-based recommendations for control of pruritus in individuals with EB.