First of all, in childhood the onset of the symptoms of dermatomyositis is comparatively acute. One one hand it consists of muscle weakness in the hip muscles. On the other hand it can affect the upper arm muscles close to the trunk (proximal muscle weakness).
Second, by the same token, in older patients this weakness is developing in a slower fashion. However, there can be a skin rash associated with it. Typically, there are also muscle aches, tenderness and pain in many joints. Especially swallowing can be a problem when the pharynx and esophagus are involved.
Fever and weight loss
Additionally, in the same fashion fever and weight loss are some non specific symptoms that are often also present. As a result of the proximal muscle involvement the patient may find it difficult in particular to walk upstairs. In case the breathing muscles are involved, certainly there might be breathing problems. This is explicitly true when challenged physically. It is important to realize that frequently muscles in hands, feet and face are usually spared (Ref. 1).
Notably, in dermatomyositis a typical purplish discoloration occurs often around the eyes (“heliotrope hue“). Altogether this is usually associated with swelling of the connective tissues around the eyes. This is called “periorbital edema“. Similar rashes may appear in other locations of the body. When the rash clears, there may be a pigmentation or thinning of the skin may develop. The skin thinning is called”atrophy”. Alternatively depigmentation, called “vitiligo”, can cause a leopard-like skin appearance.
Symptoms of dermatomyositis
- proximal muscle weakness : in upper arms, thighs, shoulders and neck flexors
- other muscle weakness : of larynx muscles causes dysphonia; of breathing muscles causes dyspnea; of pharynx and esophagus muscles causes swallowing problems
- skin involvement : multitude of appearances with purplish discoloration of skin around eyes; leopard skin from hyperpigmentations, vitiligo (see text) and skin atrophy; subcutaneous skin calcifications
- polyarthralgia : multiple joint involvement with joint swelling, effusions (non deforming)
- Raynaud’s phenomenon : often in patients with simultaneous other connective tissue diseases (see text)
- interstitial pneumonitis : lung involvement with breathing problems and cough
- gastrointestinal symptoms : more common in children: ulcerations in stomach or gut can cause blood loss
Calcifications of subcutaneous skin layers
Sooner or later calcifications of the subcutaneous skin layers tend to happen. This occurs more frequently in childhood than in adults and is another diagnostic criterion.
In more serious cases the lungs may develop a condition called “interstitial pneumonitis“. Generally speaking the patient becomes short of breath and coughs a lot. Under those circumstances, a referral to a lung specialist would lead to the diagnosis. If the physician does not diagnose dermatomyositis early, the diagnosis may get delayed by thinking that this is just a virus that hangs on.
Raynaud’s phenomenon is common. Certainly, this condition is due to a narrowing or closing off of the small blood vessels. In that case this process affects mainly toes and fingers. For this reason the Raynaud’s phenomenon is often giving rise to chronic skin ulcerations at the tip of fingers and toes.
Additionally, some parts of the toes or fingers may fall off. In like manner, an amputation may be necessary. This happens more when dermatomyositis occurs simultaneously in patients with other connective tissue diseases. Common other connective tissue diseases are Sjögren’s syndrome or lupus.
It must be remembered that gastrointestinal manifestation of dermatomyositis occurs more often in children. In them ulcerations of the gastrointestinal lining can lead to acute blood loss or to perforations with acute peritonitis. Under those circumstances where there is bleeding, there often would be vomiting of blood (upper GI bleed) or the passing of black, tarry stools (melena). In case of an acute perforation, a surgeon would need to do a surgical exploration. The surgeon may encounter a section of gut with a perforation. The surgeon removes this section of gut to restore gut function.
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