Allergic purpura (HSP) is rare in adults, and Tay et al. evaluated the incidence of cutaneous and extracutaneous manifestations of HSP and predictors of renal involvement in adults in an Asian population, with results published in The International Society of Dermatology.
Study Description
Tay et al. retrospectively studied 48 Asian adult HSP patients, mainly Chinese, Indian and Malasian, at the Third Hospital in Singapore, with HSP diagnosed according to the European League Against Rheumatism (EULAR) criteria.
The most common cutaneous manifestations of HSP were found to be palpable purpura (73%), papules (31%), and petechiae (27%). 40% of patients had lesions above the waist, 31% had gastrointestinal symptoms, 44% had joint involvement, and 56% had renal disease.
In patients with initial fever, 70% had renal involvement, while only 30% of patients without fever had renal involvement, with a significant difference. In addition, 66% of patients with purpura had renal involvement while only 31% of patients without purpura had renal involvement, a significant difference.
Adults with HSP tend to have more severe extracutaneous manifestations, especially renal disease. This study suggests that “purpura” and “initial fever” are significant predictors of renal involvement.
Additional study
Zurada et al. analyzed 31 cases of HSP, 61% had gastrointestinal symptoms, 77% had arthralgia, and 86% had renal involvement, a higher proportion than in this study, which seems to indicate that Asian patients have fewer extracutaneous manifestations, but renal involvement is most common in both populations.
Adults were at greater risk of progression to HSP nephritis than children and were associated with higher mean urine protein levels. In addition, adults require longer hospital stays and more aggressive treatment, including steroid hormones and/or immunosuppressive agents (azathioprine or cyclophosphamide).
A French study showed no correlation between renal function and purpura after 14.8 years of follow-up in patients with HSP; whereas in this study, patients with purpura had significant renal involvement compared to patients without purpura.
The authors also noted that this study was a small retrospective study with a short follow-up period of 8.63 months on average, which may affect the monitoring of malignancy and the differentiation between recent and distant renal damage. Therefore, the confirmation and generalization of the results of this study need to be confirmed by further prospective studies.