Drug Eruptions: Others

Question 1

FIXED DRUG ERUPTION
Clinical Feature
morphology:

Answer 1

sharply demarcated erythematous oval patches on the skin or mucous membranes

Question 2

FIXED DRUG ERUPTION spread:

Answer 2

commonly face, mucosa, genitalia, acral; recurs in same location upon subsequent exposure to
the drug (fixed location)

Question 3

FIXED DRUG ERUPTION

common causative agents:

Answer 3

common causative agents: antimicrobials (tetracycline, sulfonamides), anti-inflammatories,
psychoactive agents (barbiturates), phenolphthalein

Question 4

FIXED DRUG ERUPTION

Management

Answer 4

discontinue offending drug ± prednisone 1mg/kg/d x 2 wk for generalized lesions ± potent topical
corticosteroids for non-eroded lesions or antimicrobial ointment for eroded lesions

Question 5

PHOTOSENSITIVITY REACTION Clinical Feature

Answer 5

phototoxic reaction: “exaggerated sunburn” (erythema, edema, vesicles, bullae) confined to sun-exposed
areas
• photoallergic reaction: pruritic eczematous eruption with papules, vesicles, scaling, and crusting that
may spread to areas not exposed to light

Question 6

PHOTOSENSITIVITY REACTION Pathophysiology

Answer 6

phototoxic reaction: direct tissue injury

• photoallergic reaction: type IV delayed hypersensitivity

Question 7

PHOTOSENSITIVITY REACTION common causative agents

Answer 7

chlorpromazine, doxycycline, thiazide diuretics, procainamide

Question 8

PHOTOSENSITIVITY REACTION Management

Answer 8

sun protection ± topical/oral corticosteroids