Pruritus with no visible rash?

My primary diagnosed this as pruritus and prescribed Triamcinolone Acetonide Ointment about 3 years ago. In 2023, I was diagnosed with small-cell lung cancer and started chemotherapy/immunotherapy and the symptoms increased. I continue to use the Triamcinolone, but the itching continues, but not as much. I've even applied a mixture of apple cider vinegar (half and half) with water, and it soothes the itching for the moment, but it is not a cure. I'm beginning to believe it's internal and not a bacteria. I try to be mindful of my diet, cutting down on sugar and eating more plant-based organic foods. I've been to a dermatologist, and they recommended continuing the Triamcinolone, but I'm continuing to experience the itching under my arms and sometimes in my pubic area, especially when I sweat. Any suggestions.

@panache22
Sounds so familiar…have you noticed what triggers it to start? Mine is triggered by a change in temperature, even a slight change…I also have severe itch after showering, which is called Aquagenic Pruritus…but the itch is different. About 7 years ago, someone on a Facebook group for AP, discovered that when she took her workout supplements she didn’t itch…she isolated it to Beta Alanine…which is a otc amino acid supplement. I take 750 mg when the itch starts and it kills the itch…lasts for four hours…I take 1500 mg 30 mins before showering. For some strange reason, showering is far less itchy in the evening…
I believe it is some form of neuropathy. I had a full dermatology work up with no success.
I buy the NOW brand of beta alanine from Amazon in 750 capsules. The suggested dose for preworkout is much higher, 2000 mg and can cause a weird tingling on the skin. It is now recognized as a official treatment for Aquagenic Pruritus. I’ve never figured out a name for the change in temperature itch, but beta alanine works for it too…

Here are some links to Medical based websites on the subject of Aquagenic Pruritus that site Beta Alanine as a treatment, so if your dermatologist or any other doctor has looked into it, they would find the information.
I have belonged to a FB Groups for Aquagenic Pruritus for 8+ years and based on members posts, I would estimate that 99% of dermatologist have no clue.
I have been taking this for 7 years, usually 2 to 3 times per day. I have not had any issues with Beta Alanine. It is a amino acid found in our bodies...maybe I have a deficiency and that is why it works?? Who Knows...I'm just glad it works.
https://www.researchgate.net/publication/375122684_Aquagenic_Pruritus_A_web-based_survey_study_exploring_itch_characteristics_therapeutic_options_and_patient_perspectives
https://pubmed.ncbi.nlm.nih.gov/33170524/
https://my.clevelandclinic.org/health/diseases/22516-aquagenic-pruritus
https://dermnetnz.org/topics/aquagenic-pruritus

@moylandavis Hello, I am 64 years old and live in Germany. However, I have not been able to find a support group here, and I have had aquagenic pruritus since early childhood. Since I have had the same symptoms my entire life and my daughter reports similar symptoms, I assume that it is genetic. I do not have polycythemia vera and am otherwise completely healthy metabolically and do a lot of sports. However, as far as I have researched, there have been no studies to date that have been able to identify a genetic cause. I have only recently become aware of treatment with ß-alanine; previously, I thought it might cause itching. As I am a neurologist myself and know that conventional medicine can do little to help, I would like to share my experience and thoughts on my symptoms. I hope not to hurt Community Guidelines so far. Please tell me if I made a mistake. As I´m not so firm in English, I made translation via Deepl.
After a cold shower or even in a swimming pool with cold water, intense itching quickly develops, lasting about half an hour to an hour and usually spreading to the whole body. The itching can also occur spontaneously, without contact with water, and can be triggered by slight mechanical stimuli. However, frequent triggers also include light sweating with or without cooling of the skin. The pruritus has the characteristic of spreading when scratched (for relief) and eventually covering the entire body. Over the years, I have found that extremely hot, almost painful showers provide relief, and I always check first in every hotel to see if the shower is hot enough. In addition, pregabalin 75 mg is relatively effective in preventing my itching, but I do not use it regularly. When the skin is well tanned in summer, the pruritus subsides very well overall. I have experienced this frequently during vacations in the Canary Islands. When landing in humid air, the itching occurs immediately, but after the vacation with a corresponding tan, there is no more pruritus.
If the pruritus starts in one area, e.g., the thigh or forearm, I can prevent it from spreading by using a very hot water bottle, which I sometimes do when the pruritus manifests itself at bedtime. A sauna with moist heat is not a problem. Exercising in a room below 20°C and sweating is a risk factor for triggering pruritus. Trying to exercise when pruritus is starting is pointless, as it becomes unbearable. However, it is usually possible to exercise despite sweating. Occasionally, I also have the impression that excessive coffee consumption promotes pruritus. When the pruritus subsides under the effect of heat, and sometimes when it subsides spontaneously, I feel a slight burning sensation that indicates improvement. Wearing cotton clothing after showering is beneficial. Recently, I tried ß-alanine because the symptoms were getting worse again. So far, 2*1250 mg seems to have had some effect. After the first dose, I felt a slight burning sensation on my face, but otherwise there were no negative effects.
I hope that ß-alanine remains effective in my case, as it can also be used as a training booster. I wish you continued success.
PS : I read the literature you posted and I´m interested in studies to elucidate a possible genetic background.

@sportsfreund61
Wonderful to hear from a neurologist who has experience with Aquagenic Pruritus (but sorry that you suffer from this!). I sometimes think Doctors think I'm crazy. I'm glad you found my post and the links to the AP medical information and glad to hear the Beta Alanine offers some relief.

One thing I did not mention, when showering in the evening, BA works better then in the morning...I do not know why but since you mentioned a link to coffee...maybe that is the reason.

There seems to be a large percentage of People with AP also have Mast Cell Activation Syndrome. I have been successfully treated for MCAS but the AP has not been helped, only BA helps.

The good news is that there is a lot more awareness of both conditions and maybe there will be new discoveries in the near future. There have been some genes identified for MCAS and I suspect there will be more.

@moylandavis Hello, and thank you for your kind response to my comment. I have occasionally encountered MCAS in my patients. However, in Germany, proper diagnosis of this syndrome is only possible at a few specialized university hospitals. I still remember the KIT mutation. There is also an interesting story in my history. My daughter, who also suffers from occasional itching, does indeed occasionally show spontaneous local urticaria, which would suggest mast cell involvement. However, this does not occur very often. I have now also considered having genetic testing carried to look for SNV myself. I also found the high prevalence of aquagenic pruritus in Togo, which I saw in the following publication, interesting. Prevalence and Clinical Characteristics of Aquagenic Pruritus among Medical and Pharmacy Students in Lom ́e (Togo). The author summarized: "Aquagenic pruritus is a frequent affection in the study population in Togo. It occurs mainly in males. AP starts immediately or few minutes following a bath and can be generalized or localized in some parts of the body. Family cases of AP have been reported, so it is therefore important to search for a genetic factor which intervenes in the affection." Interestingly, the soothing effect of very hot water or heat itself, or prolonged exposure to UV radiation from sunlight, was not mentioned there. I once asked my health insurance company whether they would be willing to cover the costs of a genetic test. However, I think that health insurance companies will not cover these costs. If I decide to do it and verify it myself, I will report on my results in this group. Today has been good so far with ß-alanine. This morning, the pruritus wanted to return, but with ß-alanine it remained below a threshold that could be described as unpleasant and did not worsen. I wish you a pleasant and successful day.

@moylandavis /@panache22

Hopefully, y'all both see my post. Thank you for the information on the Beta Alanine. I went to my dermatologist for severe itching with no rash on my torso and thighs. She said I have Pruritus and prescribed triamcinolone acetonide. It occurs every time I'm in the sun, as if I'm allergic. I know what you are thinking. However, I own a farm in South Carolina and avoiding the blazing, humid heat is not an option. I just want to know what is causing this terrible itch. My PCP ran blood tests but found nothing.