Teste de provocação de urticária colinérgica em escada: um novo método acessível para o diagnóstico

Abstract

BACKGROUND: Cholinergic urticaria (CholU) is characterized by itching and/or stinging, painful microwheals occuring due to systemic heating. There are 2 standardized protocol to diagnose CholU using an exercise bike with heart rate or warming passive. OBJECTIVE: Describe and validate an affordable, low-tech, safe method with statistically reliable indices for the diagnosis and monitoring of CholU. METHODS: Cross-sectional study with a convenience sample; 10 with a diagnostic or high suspicion of CholU and twenty participants without suspicion of CholU, recruited in a UCARE from developing country. After pre-participation assessment, the provocation test through movements of going up and down a flight of stairs and with a heart rate monitor, an increasing 15 bpm every 5 min until an increase of 90 bpm above the initial level, for 30 min and/or stopped immediately, upon visualization of wheals and with body temperature measured in 3 different locations every 5 min. RESULTS: The UCol group consisted of eight women and two men with a median age of 28 years, and the comparison group consisted of eleven women and nine men with a median age of 27.5 years. All participants in the CholU group obtained a positive provocation test. The provocation test was positive for body temperature measured above 37.05ºC and with a variation of 0.35ºC above the initial value, providing 80% sensitivity and 100% specificity in the frontal region and 80% sensitivity and 90% specificity in the tympanic region. CONCLUSION: The provocation test was validated and showed excellent sensitivity and specificity, expanding the tools for the diagnosis of CholU, adding knowledge to the tests already described and widely used in research centers. It is expected that this accessible method for the diagnosis of CholU can be a tool for application, mainly in developing countries.