Cutaneous reactions desensitization

Fam AG, Dunne SM, lazzetta J, Paton TW. Efficacy and safety of desensitization to allopurinol following cutaneous reactions. Arthritis Rheum 2001 44(l) 231-8. 

Serious cutaneous reactions, such as exfoliative dermatitis, toxic epidermal necrolysis, and erythema multiforme buUo-sum are extremely rare. Erythema nodosum leprosum has been described during dapsone therapy, mostly in the lepro-matous type of leprosy (10). If erythema nodosnm develops before the start of therapy, the drug should be withheld until the reaction has disappeared. Severe erythema nodosum can be controlled by short-term glucocorticoid therapy. Desensitization to dapsone in patients with hypersensitivity reactions has been proposed (29). 

The cutaneous reaction caused by allopurinol is predominantly a pruritic, erythematous, or maculopapular eruption, but occasionally the lesion is urticarial or purpuric. Rarely, toxic epidermal necrolysis or Stevens-Johnson syndrome occurs, which can be fatal. The risk for Stevens-Johnson syndrome is limited primarily to the first 2 months of treatment. Because the rash may precede severe hypersensitivity reactions, patients who develop a rash should discontinue allopurinol. If indicated, desensitization to allopurinol can be carried out starting at 10—25 fjbg/day, with the drug diluted in oral suspension and doubled every 3—14 days until the desired dose is reached. This is successjul in approjdmately half of patients. Oxypurinol is available for compassionate use in the U.S. for patients intolerant of allopurinol. The safety of oxypurinol in patients with severe allopurinol hypersensitivity is unknown it is not recommended in this setting. 

Table 9.4 Oral desensitization protocols for patients with aspirin/NSAlD-induced cutaneous reactions...

Ortega N, Castillo R, Blanco C, Alvarez M, Carrillo T. Oral iron cutaneous adverse reaction and successful desensitization. Ann Allergy Asthma Immunol 2000 84(l) 43-5. 

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