The use of hot water showers in the emergency department setting has been advocated in situations where topical capsaicin cream is unavailable, though the same precautions to hot water use (dehydration, burn injury) are required.The use of antipsychotics, such as haloperidol and olanzapine, have provided complete relief of symptoms in case-reports. The evidence for the use of benzodiazepines, such as lorazepam, has shown mixed results. Other drug treatments that have been tried, with unclear efficacy, include neurokinin-1 receptor antagonists, first-generation antihistamines (e.g. diphenhydramine), 5-HT3 receptor antagonists (e.g. ondansetron), and non-antipsychotic antidopaminergics (e.g. metoclopramide).Acetaminophen has shown some benefit in case reports for alleviating headaches associated with CHS. Opioids can provide some relief of abdominal pain, but their use is discouraged due to the risk of worsening nausea and vomiting. Epidemiology
As of 2017 a French pharmacovigilance program for drug users had received reports of 29 cases of CHS. At the time there were 113 case described in the international medical literature. CHS incidence is likely to have been substantially under-reported.In the United States, an analysis of data from the National Emergency Department Sample between 2006 and 2013 found an increase in emergency room attendees with vomiting who also had cannabis use disorder, to a rate of approximately 13 per 100,000 attendees. It is possible this rise, of around 5+1⁄2 times, may be affected by sampling bias, as initial awareness of CHS prompted more diligent questioning and recording of when such ER attendees were also cannabis users.The number of people affected was unclear as of 2015.
Conditions
The following conditions are typically included in the group of seronegative spondylarthropathies:

Some sources also include Behçets disease and Whipples disease. Common characteristics
These diseases have the following conditions in common:

Seronegative (i.e. rheumatoid factor is not present)
They are in relation to HLA-B27
Inflammatory axial arthritis, generally sacroiliitis and spondylitis
Oligoarthritis, generally with asymmetrical presentation
Enthesitis (inflammation of the entheses, the sites where tendons or ligaments insert into the bone. ), e.g. Plantar fasciitis, Achilles tendinitis, costochondritis. Familial aggregation occurs
Extra-articular features, such as involvement of eyes (anterior uveitis), skin, genitourinary tract, and aortic regurgitation
Overlap is likely between several of the causative conditions

Classification
Assessment of Spondylarthritis International Society (ASAS criteria) is used for classification of axial spondyloarthritis (to be applied for patients with back pain greater than or equal to 3 months and age of onset less than 45 years). It is of two broad types:
Sacroiliitis on imaging plus 1 SpA feature, or
HLA-B27 plus 2 other SpA featuresSacroiliitis on imaging:
Active (acute) inflammation on MRI highly suggestive of SpA-associated sacroiliitis and/or
Definite radiographic sacroiliitisSpA features:
Inflammatory back pain
Arthritis
Enthesitis
Anterior uveitis
Dactylitis
Psoriasis
Crohns disease or ulcerative colitis
Good response to NSAIDs
Family history of SpA
HLA-B27
Elevated CRP

Treatment
Many patients have more than one of the spondyloarthritis disease manifestations. Some immunosuppressive drugs have shown efficacy in more than one of the diseases, e.g. tumor necrosis factor (TNF) inhibitors. But some of the immunosuppressive drugs are particularly effective for a specific inflamed tissue and approved in only one or two of the disease entities, so an interdisciplinary approach is required. Epidemiology
Worldwide prevalence of spondyloarthropathy is approximately 1.9%. References


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