A condition known as Raynaud’s phenomenon may precede the development of additional symptoms of MCTD. Raynaud’s phenomenon, which is seen also in scleroderma, is characterized by painfully cold fingers and toes with blue and/or white color changes caused by spasm of blood vessels in the hands and feet in response to cold or stress. It occurs in approximately 90 percent of individuals with MCTD.
Pain in multiple joints (polyarthralgia) or inflammation of joints (arthritis) also occurs in the majority of affected individuals. Lupus-like skin inflammation in sun-exposed areas and hair loss are common, as are skin scarring changes on the fingers and face like those seen in scleroderma. Muscle weakness due to inflammation (myositis) of proximal muscle groups can also occur. Additional frequent symptoms include hand swelling and fatigue.
Dysfunction of the esophagus occurs in at least half of individuals with MCTD. The esophagus is the tube that carries food from the mouth to the stomach. Esophageal trouble most often manifests as heartburn (gastroesophageal reflux) and difficulty swallowing solid foods. Nearly half of individuals with MCTD may develop clinically significant lung involvement, typically sometime after the condition first emerges. MCTD lung disease may lead to breathing (respiratory) difficulties caused either by high blood pressure in the lungs (pulmonary hypertension) or by causing lung inflammation and scarring in and around the air sacs (interstitial lung disease).
Heart (cardiac) involvement is less common in MCTD than lung problems, but can be serious when it occurs.
Kidney (renal) disease occurs much less often in MCTD than in lupus (10 percent of individuals with MCTD) and is often mild in MCTD.
Neurologic abnormalities are noted in approximately 10 percent of individuals with MCTD.
The low levels of circulating red blood cells (anemia) and a reduction in the white blood cell count (leukopenia) occur in 30 to 40 percent of cases. Disease of the lymph nodes (lymphadenopathy), enlargement of the spleen (splenomegaly), enlargement of the liver (hepatomegaly), and intestinal involvement may also occur in some cases.
Although medications may be required to help control MCTD, the condition has been reported to eventually enter sustained remission in as many as 40% of cases.
Among patients with MCTD, patterns of organ targeting have been reported that suggest disease subtypes. Some patients have more vascular manifestations, and have higher risk for pulmonary hypertension. Some patients have more myositis manifestations and have higher risk for interstitial lung disease. Some patients with more classic rheumatoid arthritis manifestations may have a lower risk of major internal organ damage.