How the Condition Changes Over Time

Nakajo-Nishimura Syndrome (NNS) is a progressive condition, meaning that symptoms often change and evolve as a person grows. While every person’s experience is unique, researchers have identified a “classic” progression that usually begins with skin rashes and fevers before moving toward changes in body shape and joint mobility ^[1][2].

It is important to distinguish between symptoms of active inflammation (which fluctuate and may respond to medication) and established changes (which are often permanent) ^[1].

The First Signs: Rashes and Fevers

For most people, the earliest signs of NNS involve the skin and the body’s internal thermostat. These symptoms often appear in infancy or early childhood and may include:

• Periodic Fevers: These are fevers that come and go at somewhat regular intervals ^[2]. In some cases, cold weather seems to trigger or worsen these fever episodes ^[3].
• Pernio-like Lesions: You may notice red or purplish patches on the nose, cheeks, hands, and feet ^[4]. These often look like chilblains (painful inflammation of small blood vessels in response to cold) ^[2].
• Panniculitic Nodules: These are tender, red bumps that usually form under the skin ^[2]. They are caused by panniculitis, which is inflammation of the fat layer just beneath the skin’s surface ^[5].

Changes in Appearance: Lipomuscular Atrophy

As the condition progresses, a hallmark of NNS is the loss of both body fat and muscle, a process called lipomuscular atrophy ^[4]. This typically follows a specific pattern:

• Upper Body Focus: The loss of fat and muscle is usually most noticeable in the face, neck, and upper trunk ^[2]. A person may develop a very thin appearance in these areas while the lower body remains less affected ^[2].
• Muscle Weakness: Along with the loss of fat, the muscles themselves can be affected ^[1]. This weakness can be due to active muscle inflammation (myositis), but it can also reflect established atrophy, joint stiffness, or deconditioning ^[1].
• Cellular Stress: This loss happens because the defective proteasome function causes cellular stress and chronic inflammatory signaling that impacts the fat and muscle tissue ^[6][7].

Hand and Joint Changes

The inflammation in NNS also affects the small joints and the shape of the fingers and toes.

• Clubbed Fingers: Many people develop fingers and toes that appear unusually long and have widened, rounded tips, known as clubbing ^[4].
• Joint Contractures: Over time, chronic inflammation and muscle loss can lead to joint contractures, where the joints become stiff and fixed in a bent position ^[4]. This most commonly affects the fingers, making it hard to fully straighten the hand ^[2].
• Acrocyanosis: The fingers and toes may also appear blue or cold, especially in lower temperatures, due to changes in blood flow ^[3].

Systemic (Body-Wide) Involvement

Because NNS is a systemic inflammatory disease, it can affect internal organs and the brain in ways that aren’t visible from the outside.

• Organ Enlargement: Some individuals may develop an enlarged liver (hepatomegaly) or spleen (splenomegaly) as the immune system remains in a state of high alert ^[4][2].
• Basal Ganglia Calcification: In some cases, imaging ordered for specific neurologic findings may show small calcium deposits in the basal ganglia, a part of the brain that helps control movement ^[2][4].
• Amyloidosis Risk: In rare instances of long-term, uncontrolled inflammation, a protein called amyloid can build up in the organs, particularly the kidneys. This is known as AA amyloidosis and requires close medical monitoring ^[3].

The severity of these symptoms can vary widely. Some people may have very mild skin signs for years, while others may experience more rapid progression of muscle weakness and fat loss ^[1][3]. Consistent monitoring by a team of specialists is the best way to track these changes and adjust treatments as needed.