Page 517 - First Aid for the USMLE Step 1 2020, Thirtieth edition [MedicalBooksVN.com]_Neat

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dERmatology

Musculoskeletal, skin, and connective tissue ` pathology Don’t delete section iii 473
Musculoskeletal, skin, and connective tissue ` dERmatology

Scleroderma Systemic sclerosis. Triad of autoimmunity, noninflammatory vasculopathy, and collagen deposition
with fibrosis. Commonly sclerosis of skin, manifesting as puffy, taut skin A without wrinkles,
fingertip pitting B . Can involve other systems, eg, renal (scleroderma renal crisis; treat with ACE
inhibitors), pulmonary (interstitial fibrosis, pulmonary HTN), GI (esophageal dysmotility and
reflux), cardiovascular. 75% female. 2 major types:

ƒ Diffuse scleroderma—widespread skin involvement, rapid progression, early visceral
involvement. Associated with anti-Scl-70 antibody (anti-DNA topoisomerase-I antibody) and
anti-RNA polymerase III.
ƒ Limited scleroderma—limited skin involvement confined to fingers and face. Also with
CREST syndrome: Calcinosis cutis C , anti-Centromere antibody, Raynaud phenomenon,
Esophageal dysmotility, Sclerodactyly, and Telangiectasia. More benign clinical course.
A B C

` mUsCUlosKElEtal, sKin, and ConnECtiVE tissUE—dERmatology

Skin layers Skin has 3 layers: epidermis, dermis, subcutaneous fat (hypodermis, subcutis).
Epidermal layers: Come, Let’s Get Sun Burned.

A
Stratum Corneum

Stratum Lucidum

Stratum Granulosum

Stratum Spinosum

Stratum Basalis

Dermis

FAS1_2019_11-Musculo.indd 473 11/7/19 5:24 PM