In the past I have written about histamine intolerance[ Mar 2014] being a possible CFS mechanism. I also wrote about Non-histamine probiotics. After that post, there was a 2015 paper on Mast Cell and Autoimmune Diseases (“Mast Cells promote inflammation in the same way like TNF”). In this post, I want to look at what we know about specific bacteria that may cause itching, hives, or to use the medical term , urticaria. Medical opinion is that all of these are due to histamine release, so we are effectively looking at bacteria that can cause histamine to be release from mast cells.
- Helicobacter pylori: A significant and treatable cause of chronic urticaria and angioedema. 
- “Mycoplasma pneumoniae has been shown to be an important cause of common disorders such as urticaria,”  – incidence of mycoplasma infections in CFS populations is much higher than the general population. [Systemic Mycoplasma blood infection in fibromyalgia and chronic fatigue syndrome].
- ” Many bacterial infections have been associated with urticaria manifestation, such as Helicobacter pylori, Streptococcus, Staphylococcus, Mycoplasma pneumonia, Salmonella, Brucella, Mycobacterium leprae, Borrelia, Chlamydia pneumonia, and Yersinia enterocolitica.” 
- Our old “friend” Staphylococcus aureus post[with herbs to address] is cited in this  paper
- Herpesvirus-associated acute urticaria: an age matched case-control study.
- Is inherited human herpesvirus 6 the perpetrator behind some cases of chronic fatigue syndrome? 
- Association of active human herpesvirus-6, -7 and parvovirus b19 infection with clinical outcomes in patients with myalgic encephalomyelitis/chronic fatigue syndrome. 
- Serological and virological investigation of the role of the herpesviruses EBV, CMV and HHV-6 in post-infective fatigue syndrome. 
- Activation of human herpesviruses 6 and 7 in patients with chronic fatigue syndrome. 
There are many virus and bacteria that are associated with urticaris — which I assume is primarily caused by histamine release. IMHO, Staphylococcus it the preferred one to initially target and there was a pub med reports in 2001 of eradication of Staphylococcus leading to CFS remission. As well as staphylococcus toxoid on FM and CFS resulting in major positive results in 2002.
I have updated my staphylococcus aureus-the-cfs-maintainer post with more herbs and spices that have evidence on PubMed of being effective. One word of caution, some may dump chemicals triggering histamine release when they are killed — so have DAO and anti-histamine handy!