FCAS, MWS, and NOMID all fall under CAPS with mutations in the same gene and share some overlapping symptoms. However, each has unique distinctions and there can also can be a high degree of variability of symptoms and severity even between patients who fall under the same category. Here are some of the ways that these three conditions compare.
Familial cold autoinflammatory syndrome typically involves a periods (usually around 24 hours) of a fever, rash and joint pain after exposure to cold temperatures and occasionally muscle pain or conjunctivitis. It is common for FCAS to be symptomatic at birth or within the child’s first six months. Check out Patient Worthy’s article You Know You Have FCAS When… for more on FCAS.
Muckle-Wells Syndrome also often involves fever, rash and joint and eye inflammation but fatigue is typically more frequent than fever and exposure to cold temperatures is not often a trigger for attacks. Another distinction between FCAS and MWS is the prevalence of deafness; according to Pediatric Rheumatology International Trials Organisation or PRINTO, it occurs in about 70% of MWS patients. A serious condition experienced by about 25% of MWFS patients in adulthood is the deposition of the inflammatory protein, amyloid, which can impair renal function.
Chronic Infantile Neurologic Cutaneous Articular syndrome or Neonatal Onset Multi-systemic Inflammatory Disease is the most severe CAPS condition. It typically presents itself with a rash in early infancy. Similarly to MWS, fatigue is typically a symptom more frequently than fevers. Joint and bone inflammation can, in mild cases result in swelling, and in severe cases result in the overgrowth of cartilage(overgrowth arthropathy), which often tend to occur in early childhood. As stated by PRINTO, “Abnormalities of the central nervous system (CNS) are present in almost all patients and are caused by chronic aseptic meningitis (non-infectious inflammation of the membrane surrounding the brain and spinal cord).” This, in turn, results to increased intracranial pressure which can cause headaches and even, in the most severe cases, epilepsy or cognitive impairment. Perceptive deafness is fairly common.
Read more on CAPS here.
Featured image sourced from The Stir