Familial Cold Autoinflammatory Syndrome is the most common CAPS subtype in the United States.

• Symptoms: Rash, headache, fever or chills, feeling tired, sore or red eyes, muscle pain, or joint pain
• Onset of symptoms: At birth or, rarely, later in childhood
• Trigger of symptoms: Exposure to cold temperatures
• Duration of symptoms: Episodes typically last no more than 24 hours

Muckle-Wells Syndrome is more severe than FCAS.

• Symptoms: Those symptoms listed for FCAS, as well as loss of hearing and kidney damage
• Onset of symptoms: Adolescence, but it can occur at any age
• Trigger of symptoms: Exposure to cold temperatures, physical stress, or other reasons that are not yet known
• Duration of symptoms: Episodes usually last 1 to 2 days

Neonatal-Onset Multisystem Inflammatory Disease is the most severe subtype of CAPS. Even fewer people have this disease than the 2 subtypes mentioned above.

• Symptoms: All of the above-mentioned symptoms, as well as loss of eyesight, abnormal bone growth in the knees, and developmental problems
• Onset of symptoms: Almost always at birth
• Trigger of symptoms: Reasons that are not yet known
• Duration of symptoms: Continuous, with symptoms worsening from time to time