Fixed drug eruption following metronidazole therapy and the use of topical provocation testing in diagnosis

Abstract

Fixed drug eruption is characterized by recurrent well-defined lesions appearing in the same location each time the drug responsible is taken. A number of agents have been implicated. Metronidazole, a nitroimidazole agent widely used for its antibacterial and antiprotozoal activity, has been reported only rarely as the causative agent. We describe a patient with FDE due to metronidazole in whom we were able to induce the clinical and histological features of FDE by topical provocation testing. In agreement with the published literature we commend the use of topical provocation testing as a possible first-line investigation in the diagnosis of FDE. This may avoid the need for subsequent oral provocation testing and therefore the prevention of possible adverse sequelae.

An isotopic response to patch testing

“…This may be due to localized changes in vascularity and vascular permeability or to the presence of a chronic inflammatory infiltrate including memory T cells. Comparisons may be drawn with a fixed drug eruption, where an increase in expression of intracellular adhesion molecule‐1 on lesional keratinocytes, following first exposure to the drug, is thought to provide a localized‐initiating stimulus for activation of disease‐associated epidermal T cells on subsequent exposure (4). In our case, reactivation of eczema as the result of patch testing may have acted as the trigger.…”

Bullous Fixed Drug Eruption Induced by Intravaginal Metronidazole Ovules, With Positive Topical Provocation Test Findings

“…1 It is a diagnosis of exclusion based on persistent discomfort, most often described as burning pain, that is present without objective cutaneous findings and no identifiable infectious, inflammatory, neoplastic, or neurologic cause. 1 It is a diagnosis of exclusion based on persistent discomfort, most often described as burning pain, that is present without objective cutaneous findings and no identifiable infectious, inflammatory, neoplastic, or neurologic cause.…”

“…1 Localized provoked vulvodynia is the most common subtype and is usually triggered by sexual activity or tampon insertion. Bowen et al 3 found that 61% of patients referred to a tertiary vulvovaginal clinic for chronic vulvar pain had a clinically relevant dermatologic condition; therefore, dermatologists may play a primary role in the care of these patients.…”

Fixed drug eruption induced by tipepidine hibenzate

“…Sixteen cases of drug eruption caused by TH were reported; 1 10 of these cases involved children and were all FDE. Patch testing on the site of previously affected skin is safe and useful for confirming the drug responsible for the FDE 2,3 . However, in the child cases above of FDE, only one patient was positive in patch test, whereas the oral challenge test was required for diagnosis in the remaining nine cases.…”

“…However, in the child cases above of FDE, only one patient was positive in patch test, whereas the oral challenge test was required for diagnosis in the remaining nine cases. Generally, negative results for the patch tests were attributed to inadequate transepidermal absorption 2,3 or to lack of metabolic modification of the drugs in the gastrointestinal tract or liver 4 . Therefore, in the event of a negative LST result or a patch test for a suspected case of FDE by TH, an oral challenge test should be performed to avoid subsequent prescription and resulting in systemic involvement, such as Stevens–Johnson syndrome 5 …”