A patient with a fixed drug reaction often has a single lesion, and the lesion will occur in the same location every time the patient is exposed to the drug.
If the eruption has occurred before, that factor suggests that a diagnosis of erythema multiforme or fixed drug reaction may be more likely than TEN.
The most common type of offending drugs causing the drug reactions are sulfonamides in 8 (40%) cases followed by NSAIDs in 6 (30%) quinolones 3 (15%) metronidazole in 2 (10%) cases and anticonvulsants in 1(5%) case similar to the study finding of Patel et al.9 where majority of causative drugs in fixed drug reaction
were co-trimoxazole 26 (29.5%) and NSAIDs 20 (22.8%) in number.
The differential diagnosis included Behcet's disease, cicatricial pemphigoid, a fixed drug reaction, and allergic contact dermatitis.
* A fixed drug reaction is an allergic reaction to a particular medication that occurs at the same location whenever that medication is taken.
6 52 F Ciprofloxacin, Mefenamic Fixed drug reaction
acid, Acetaminophen, affecting multiple Diclofenac sodium, sites with oral Cefadroxyl erosions 7 42 F Diclofenac sodium, Urticaria Ampicillin, Cetirizine.
It is especially important to rule out herpes simplex, varicella, bullous tinea, bullous fixed drug reaction
, bullous drug eruption, and staphylococcal scalded skin syndrome.
Again, more than 75% of drug reactions present with dermal manifestations (urticaria, angioedema, fixed drug reactions
Fixed Drug Reactions
. Following a primary episode of allergic skin/mucosal eruption induced by a drug-specific T cell-mediated hypersensitivity immune reaction in response to exposure to a systemic drug, reexposure to the same or to a chemically closely related drug may induce a recurrent eruption at the same site.
Fixed drug reactions
have been reported for indomethacin, aspirin, mefenamic acid, diclofenac, piroxicam and paracetamol.