From the Guidelines
Allopurinol and Delayed Pruritic Skin Reaction
Allopurinol can cause a delayed pruritic skin reaction, typically occurring within 2-6 weeks after initiation of therapy, characterized by itchy skin and often manifesting as a morbilliform or maculopapular rash, accompanied by pruritus 1.
- The reaction is often observed at standard doses of 100-300 mg daily.
- The onset of this reaction can be delayed, sometimes occurring after several months of treatment, highlighting the importance of ongoing monitoring for adverse effects in patients receiving allopurinol 1.
- Serious adverse effects, including fatal hypersensitivity reactions, have been reported with allopurinol, particularly in individuals with the HLA-B*5801 haplotype, which is prevalent in certain ethnic groups, including Asian and Korean persons with stage 3 or worse chronic kidney disease 1.
- It is essential to note that while the most common adverse event with allopurinol is rash, most serious adverse effects are rare, mild, and reversible 1.
- The evidence suggests that allopurinol-induced hypersensitivity reactions can be severe and may require hospitalization and treatment with prednisolone, as seen in a case study where a patient developed a generalized maculopapular exanthema, fever, and eosinophilia after starting allopurinol 1.
- Ongoing monitoring for adverse effects is crucial in patients receiving allopurinol, given the potential for delayed and severe reactions.
From the FDA Drug Label
The most frequent adverse reaction to allopurinol tablets is skin rash. Skin reactions can be severe and sometimes fatal Therefore, treatment with allopurinol tablets should be discontinued immediately if a rash develops Among 55 patients with gout treated with allopurinol tablets for 3 to 34 months (average greater than 1 year) and followed prospectively, Rundles observed that 3% of patients developed a type of drug reaction which was predominantly a pruritic maculopapular skin eruption, sometimes scaly or exfoliative. It has been reported that symptoms may develop in approximately 1 week from initiating allopurinol therapy, but longer latency periods have also been reported.
Yes, allopurinol can cause a delayed pruritic skin reaction 2.
From the Research
Allopurinol and Skin Reactions
- Allopurinol has been associated with various adverse effects, including skin reactions 3, 4.
- A study published in 2015 found that 2 patients (4.5%) in the treatment group had minor skin reactions after receiving allopurinol for 12 weeks 5.
- However, there is no specific mention of a delayed pruritic skin reaction in the provided studies.
- The studies primarily focus on the efficacy and safety of allopurinol in treating hyperuricemia, gout, and its effects on blood pressure and renal function 3, 4, 6, 7, 5.