include the following.
the psoriasis is active, lesions can appear in skin damaged by scratches or
surgical wounds (the Köbner phenomenon; Fig. 5.1).
strep-tococci often triggers guttate psoriasis. AIDS often worsens it, or
precipitates explosive forms.
frequently improves in preg-nancy only to relapse postpartum. Hypocalcaemia
secondary to hypoparathyroidism is a rare precipitat-ing cause.
most psoriatics but 10% become worse.
5 Drugsaantimalarials,βblockers, IFN-αand
lith-ium may worsen psoriasis. Psoriasis may ‘rebound’ after withdrawal of
treatment with systemic steroids or potent topical steroids. The case against
non-steroidal anti-inflammatory drugs (NSAIDS) remains unproven.
6 Cigarette smoking and alcoholathe effects of con-founding variables have been difficult to unravel in most epidemiological studies but there is growing evidence that both have an independent effect in pre-cipitating or maintaining psoriasis.
upsets seem to cause someexacerbations.