If allopurinol toxicity occurs, options include other xanthine oxidase inhibitors, a uricosuric agent, or allopurinol desensitisation (the latter only in cases of mild rash).
Clinicians should maintain a high index of suspicion for vaccinia when evaluating vesiculopapular rashes in patients who have been vaccinated recently and in their close contacts.
Several distinct rickettsiae (a parasite carried by ticks, fleas, and lice) cause a disease known as typhus in humans.All cause disease with similarities of fever, headache, and rash.