Dermatomyositis

Dermatomyositis REF: Harrison’s 17^th e chapter 382

Dermatomyositis

• DM is a distinctive entity identified by a characteristic rash accompanying, or more often preceding, muscle weakness.
• The rash may consist of a blue-purple discoloration on the upper eyelids with edema heliotrope rash a flat red rash on the face and upper trunk
• Erythema of the knuckles with a raised violaceous scaly eruption Gottron’s sign.
• The erythematous rash can also occur on other body surfaces, including the knees, elbows, malleoli, neck and anterior chest (often in a V sign), or back and shoulders (shawl sign), and may worsen after sun exposure.

Dermatomyositis REF: Harrison’sl7th ed chapter 383 ‘.

DERMATOMYOSITIS

DM is a distinctive entity identified by a characteristic rash accompanying, or more often preceding, muscle weakness. The rash may consist of a blue-purple discoloration on the upper eyelids with edema (heliotrope rash) a flat red rash on the face and upper trunk, and erythema of the knuckles with a raised violaceous scaly eruption (Gottron’s sign).

The erythematous rash can also occur on other body surfaces, including the knees, elbows, malleoli, neck and anterior chest (often in a V sign), or back and shoulders (shawl sign), and may 1/4     worsen after sun exposure.

In some patients the rash is pruritic, especially on the scalp, chest, and back. Dilated capillary loops at the base of the fingernails are also characteristic. The cuticles may be irregular, thickened, and distorted, and the lateral and palmar areas of the fingers may become rough and cracked, with irregular, “dirty” horizontal lines, resembling mechanic’s hands.

Gottron’s sign is a characteristic feature of dermatomyosistis.

It is a violaceous, erythematous, symmetrical rash that occur on the extensor surface of the metacarpophalangeal and interphalangeal joints. Similar lesions can also occur over the elbow and knees.

Dermatomyositis (DM):

• DM is a distinctive entity identified by a characteristic rash accompanying, or more often preceding, muscle weakness. 
• The rash may consist of a blue-purple discoloration on the upper eyelids with edema (heliotrope rash).  
• A flat red rash on the face and upper trunk, and erythema of the knuckles with a raised violaceous scaly eruption (Gottron’s sign). 
• The erythematous rash can also occur on other body surfaces, including the knees, elbows, malleoli, neck and anterior chest (often in a V sign), or back and shoulders (shawl sign), and may worsen after sun exposure. 
• The lateral and palmar areas of the fingers may become rough and cracked, with irregular, “dirty” horizontal lines, resembling mechanic’s hands.

• Gottron papules: These are papules with a violaceous hue which are typically found over the dorsal–lateral aspect of interphalangeal and/or metacarpophalangeal joints.
• Heliotrope rash: Is a periorbital confluent macular violaceous erythema of the eyelids and periorbital tissue.
• Periungual telangiectasia
• Symmetric confluent macular violaceous erythema: When seen over the posterior shoulders and neck its called shawl sign, and  when on the  anterior neck and upper chest its called V sign.
• Mechanic’s hand lesion: Are areas of bilaterally symmetric confluent hyperkeratosis.

Pulmonary involvement is seen in 35% or scleroderma. It is also fairly common in rheumatoid arthritis. It is seen in only 10% Dermatomyositis.

Dermatomyositis is considered to be the result of a humoral attack against the muscle capillaries and small arterioles (endothelium of the endomysial blood vessels).

Extramuscular manifestations of the disease may include the following:

• General systemic disturbances, fever, arthralgia, malaise, weight loss, Raynaud phenomenon
• Dysphagia, similar to that of scleroderma
• Atrioventricular defects, tachyarrhythmias, dilated cardiomyopathies
• GI ulcers and infections
• Contracture of joints
• Pulmonary involvement due to weakness of thoracic muscles, interstitial lung disease (least common)

Ans. is ‘b’ i.e., Dermatomyositis

o Dermatomyositis is a connective-tissue disease related to polymyositis that is characterized by inflammation of the muscles and the skin.

o It is a systemic disorder that may also affect the joints, the esophagus, the lungs, and, less commonly, the heart.

o On the muscle biopsy, there are two classic microscopic findings of dermatomyositis. They are : mixed B- & T-cell perivascular inflammatory infiltrate and perifascicular muscle fiber atrophy.

o It is associated with autoantibodies, especially anti-Jol antibody.

Ans. is ‘d’ i.e., Dermatomyositis

Muscle biopsy in dermatomyositis shows myonecrosis, myophagocytosis and perifascicular atrophy.

A i.e. Gottron papules

A i.e. Dermatomyositis

B i.e. Dermatomyositis

Answer is A (Salmon Patch):

Salmon patch is not a feature of dermatomyositis.

Cutaneous features of dermatomvositis

Ans:D- Dermatomyositis

A heliotrope rash is characteristic of dermatomyositis.

Dermatomyositis is part of a group of muscle diseases called inflammatory myopathies or myositis (inflammation of muscle).

Dermatomyositis is a chronic autoinflammatory disease, with symptoms that may change over time. 

About a third of people who develop dermatomyositis as children recover, but the remainder continue to experience symptoms

The given image shows Gottron’s sign i.e  Confluent macular erythema with scale confined to the skin overlying the patellae in a patient with  dermatomyositis.

Dermatomyositis (DM) is a connective-tissue disease related to polymyositis (PM) that is characterized by inflammation of the muscles and the skin. While DM most frequently affects the skin and muscles, it is a systemic disorder that may also affect the joints, the esophagus, the lungs, and the heart

Gottron sign: A scaly, patchy redness over the knuckles seen in patients with dermatomyositis, an inflammatory muscle disorder.

Dermatomyositis (DM) is a connective-tissue disease related to polymyositis (PM) that is characterized by inflammation of the muscles and the skin. While DM most frequently affects the skin and muscles, it is a systemic disorder that may also affect the joints, the esophagus, the lungs, and the heart.

The condition shown in the picture above is Gottron’s papules.

Gottron’s sign or Gottron’s papules – Gottron’s sign is a flat red rash over the back of the fingers, elbows or knees. Gottron’s papules are red, often scaly, bumps overlying the knuckles of the fingers.

Ans. is ‘a’ i.e., Dermatomyositis