Symptoms include skin rashes, severe arthritis, and chronic meningitis leading to neurologic damage.

The presence of the rash varies with time, and biopsy of these skin lesions shows a perivascular inflammatory infiltrate including granulocytes.

Joint signs are variably expressed and can lead to transient swelling without sequelae between crises, or to unpredictable anomalies of growth cartilage and long bones epiphyses suggestive of a pseudo-tumour.

These manifest themselves in three principal ways: chronic meningitis, involvement of both the optic tract and eye, and sensorineural hearing loss.

Ocular manifestations occur in 80% of cases and include uveitis (70%), papillary involvement, conjunctivitis, and optical neuritis.

The sensorineural hearing loss occurs in 75%, and tends to be progressive leading to deafness in 20% of cases.

Other findings that have been reported include macrocephaly (95%), large fontanelle, prominent forehead, flattening of the nasal bridge (saddleback nose), short and thick extremities, and finger clubbing.

[citation needed] The diagnosis is based on observing the patient and finding the constellation of symptoms and signs described above.

[citation needed] Routine laboratory investigations are non-specific: anaemia, increased numbers of polymorphs, an elevated erythrocyte sedimentation rate and elevated concentrations of C-reactive protein are typically all the abnormalities found.

These changes include bony overgrowth due to premature ossification of the patella and the long bone epiphyses in very young children and bowing of long bones with widening and shortening periosteal reaction in older ones.

MRI with contrast may show enhancement of leptomeninges and cochlea consistent with chronic meningitis.

[citation needed] Overall, the prognosis for patients with NOMID is not good, though many (80%) live into adulthood, and a few appear to do relatively well.

They are at risk for leukemia, infections, and some develop deposits of protein aggregated called amyloid, which can lead to kidney failure and other problems.

[citation needed] This is a rare condition with an incidence estimated to be less than 1 in a million live births.