Cholinergic Urticaria – Heat Induced Hives are a Real Itch
Cholinergic urticaria is an interesting and uncommon inducible urticaria that results in hives or wheals when an affected individual experiences a rise in their core body temperature. This can occur during a hot bath, during mental or emotional stress, or while eating spicy foods.
There is limited research on cholinergic urticaria, so there is still much to be discovered.
Current studies suggest that young adults are more likely to be affected than adults and that women tend to be affected more than men. (Fricke, 2019)
Cholinergic urticaria is considered chronic inducible urticaria as hives continue to occur for more than 6 weeks and are caused by a specific physical or environmental stimulus. (Pozderac, 2020)
The main symptom of cholinergic urticaria is the development of hives/wheals on the body after an increase in body temperature.
The hives develop within minutes and can last up to 2 hours. Although it is reported the hives usually last between 1-2 hours. (Moore, n.d.) The wheals vary in size and range from around 1-5 mm. (Kim, 2014) In cholinergic urticaria, the most common places hives develop are the limbs and trunk.
The hives are reported to cause an itchy or burning sensation similar to what is experienced after an insect bite. Individuals may also experience the following symptoms:
- Chest tightness
While extremely rare, some individuals may experience life threatening symptoms such as angioedema or anaphylaxis.
Angioedema is a painless swelling under the skin. It can be life-threatening if swelling of the airway occurs.
Anaphylaxis is a severe allergic reaction that affects the whole body. This can result in the following symptoms:
If not treated promptly, an anaphylactic reaction can turn deadly.
The exact cause of cholinergic urticaria is not fully understood.
There is preliminary data that suggests there could be a genetic component, but more research needs to be done in order to substantiate this claim. (Onn, 1996)
As previously discussed, an increase in core body temperature is the trigger that induces urticaria.
Extensive diagnostic procedures are not necessary to diagnose cholinergic urticaria.
Typically, a positive medical history is enough for a diagnosis. However, provocation tests are available to confirm cholinergic urticaria. Provocation testing is performed via an exercise challenge.
The exercise challenge involves the participant exercising up until the point of sweating (up to 15 minutes or more). If within 10 minutes of exercise a rash develops, then the result is positive.
A warming test can also be done 24 hours later to differentiate between cholinergic urticaria and exercise-induced anaphylaxis. The warming test involves submerging the participant for up to 15 minutes in a 108-degree Fahrenheit bath while recording core body temperature. If a rash develops, then the result is positive for cholinergic urticaria.
Treatment for cholinergic urticaria
The main recommendation for cholinergic urticaria is to avoid triggers.
However, attempting to prevent a reaction from occurring could result in a decrease in quality of life. For instance, exercise and physical activity is an important part of living a healthy lifestyle. Enjoying outside activities in the warm weather can also be an enjoyable way to spend time with friends and family.
For this reason, treatment may focus on controlling symptoms rather than preventing them from occurring altogether.
The alternative to avoiding triggers is for individuals to take medications such as antihistamines to help decrease the severity of symptoms. Antihistamine medications are medications that are usually taken to treat allergies. They work by blocking a substance known as histamine which is the chemical that results in allergy symptoms.
The following medications have been suggested to reduce the severity of symptoms:
- Loratadine (Zyrtec)
- Fexofenadine (Allegra)
- Hydroxyzine (Vistaril)
It is recommended that the antihistamines are taken several hours prior to the onset of physical activity or an event that may cause an increase in core body temperature.
As mentioned, much research still needs to be done about cholinergic urticaria.
Individuals with cholinergic urticaria must take preventative measures to reduce the severity of their symptoms.
The best practice is to take a daily antihistamine and avoid triggers when possible.
Fricke, J., Avila, G., Keller, T., Lau, S., Maurer, M., Zuberbeir, T., & Keil, T. (2019). Prevalence of chronic urticaria in children and adults across the globe: Systematic review with meta-analysis. European Journal of Allergy and Clinical Immunolgoy, 75(2), 423-432. https://doi.org/10.1111/all.14037
Kim, J. E., Eun, Y. S., Park, Y. M., Park, H. J., Yu, D. S., Kang, H., Cho, S. H., Park, C. J., Kim, S. Y., & Lee, J. Y. (2014). Clinical characteristics of cholinergic urticaria in Korea. Annals of dermatology, 26(2), 189–194. https://doi.org/10.5021/ad.2014.26.2.189
Moore, G., Gupta, M., & Oakley, A. (n.d.). Heat urticaria. DermNet. https://dermnetnz.org/topics/heat-urticaria
Onn, A., Levo, Y., & Kivity, S. (1996). Familial cholinergic urticaria. The Journal of allergy and clinical immunology, 98(4), 847–849. https://doi.org/10.1016/s0091-6749(96)70137-9
Pozderac, I., Lugović-Mihić, L., Artuković, M., Stipić-Marković, A., Kuna, M., & Ferček, I. (2020). Chronic inducible urticaria: classification and prominent features of physical and non-physical types. Acta dermatovenerologica Alpina, Pannonica, et Adriatica, 29(3), 141–148.
Schoepke, N., Doumoulakis, G., & Maurer, M. (2013). Diagnosis of urticaria. Indian journal of dermatology, 58(3), 211–218. https://doi.org/10.4103/0019-5154.110831
Sijapati, N., Sciturro, M., Le, M., Lanza, J., Mercado, E., & Seferovic, A. (2022). Exercise-Induced Urticaria: A Rare Case Report. Cureus, 14(3), e23062. https://doi.org/10.7759/cureus.23062
Zuberbier, T., Althaus, C., Chantraine-Hess, S., & Czarnetzki, B. M. (1994). Prevalence of cholinergic urticaria in young adults. Journal of the American Academy of Dermatology, 31(6), 978–981. https://doi.org/10.1016/s0190-9622(94)70267-5
Holly Myers is a registered nurse and health writer who obtained her BSN from UTA in 2017. She has worked in a broad range of specialties which has provided her with a deep understanding of health and wellness. She enjoys maintaining an active lifestyle through exercise and gardening, as well as spending quality time with her two boys. Her passion for health and wellness, coupled with her love of writing, makes her a valuable resource for anyone seeking reliable health information.