Page 515 - First Aid for the USMLE Step 1 2020, Thirtieth edition [MedicalBooksVN.com]_Neat

Musculoskeletal, skin, and connective tissue ` pathology Musculoskeletal, skin, and connective tissue ` pathology section iii 471

Fibromyalgia Most common in women 20–50 years old. Chronic, widespread musculoskeletal pain associated
with “tender points,” stiffness, paresthesias, poor sleep, fatigue, cognitive disturbance (“fibro
fog”). Treatment: regular exercise, antidepressants (TCAs, SNRIs), neuropathic pain agents (eg,
gabapentin).

Polymyositis/ Nonspecific: ⊕ ANA,  CK. Specific: ⊕ anti-Jo-1 (histidyl-tRNA synthetase), ⊕ anti-SRP (signal
dermatomyositis recognition particle), ⊕ anti-Mi-2 (helicase).
Polymyositis Progressive symmetric proximal muscle weakness, characterized by endomysial inflammation with
CD8+ T cells. Most often involves shoulders.
Dermatomyositis Clinically similar to polymyositis, but also involves Gottron papules A , photodistributed facial
erythema (eg, heliotrope [violaceous] edema of the eyelids B ), “shawl and face” rash C ,
darkening and thickening of fingertips and sides resulting in irregular, “dirty”-appearing marks.
 risk of occult malignancy. Perimysial inflammation and atrophy with CD4+ T cells.
A B C

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