Fig. 25.1 Exanthem over legs developing a violaceous hue before scaling. This patient had been on clindamycin for many weeks and developed this skin eruption, which generalized with time. He…
Fig. 7.1 Atypical target lesions with dusky center (typical of people of color) and surrounding erythema in a patient who flares with episodes of genital HSV Historical Perspective In 1866,…
Drug eruption-like pityriasis rosea Gilbert’s pityriasis rosea Absence of initial single herald patch Presence of initial single herald patch Bright violet-red lesions Salmon-pink lesions Pruritus unrelieved by antihistamines Pruritus relieved…
Fig. 6.1 Symmetric urticarial drug eruption due to cephalexin over the back. This was acute and discontinuation of the drug resulted in rapid resolution Antibiotics: penicillins, cephalosporins, macrolides, aminoglycosides, tetracyclines,…
Fig. 11.1 Symmetrically distributed on the anterior shins there are erythematous, warm, indurated plaques that were confirmed to be EN on histopathology Fig. 11.2 A close-up of the lesions of…
Fig. 12.1 Dramatic hyperpigmentation over the back in a patient on gold therapy. The biopsy was compatible with a lichenoid drug eruption. The newer lesion on the upper back show…
Mediator Mechanism(s) Clinical phenotypes Type I Immediate IgE Ag binding to mast cell/basophil surface receptors Urticarial, anaphylaxis, angioedema Type II Antibody-mediated (cytotoxic) IgM, IgG Ab binds to Ag leading…
Allergic Toxic Clinical Urticaria, morbilliform, etc. Mimics action of drug Histopath Nonspecific Mimics action of drug Dose of drug Not dose-related, idiosyncratic Less dose may cure; Universal at high…
