(1997; 132 pages) [French] [Spanish]
Solar urticaria, which is probably immunologically mediated, is characterized by the transient appearance of wheals, lasting from a few minutes to one hour. These may be single or multiple, and they develop within minutes of exposure to strong sunlight.
Antihistamines are of limited value, but long-term administration of chloroquine is claimed to increase the tolerance of the skin to sunlight. However, irreversible visual impairment resulting from accumulation of chloroquine in the retina may occur during long-term treatment. Patients should therefore be monitored closely.