Dermis and Subcutaneous Tissue

Question 1

What are the structural components of the dermis?

Answer 1

the extracellular matrix includes collagen, elastic fibers and glycoportiens, proteoglyans and hyaluraonic acid

blood vessels, nerves

adnexal structures: hair, eccine, sebaceous and apocrine glands

cells including dermal dentrocytes, fibroblasts, macrophages, mast cells

Question 2

What is the function of the dermis?

Answer 2

provide support, strength, elasticity and shape of the skin, allows the subcutaneous tissue to resist outside forces and underlying structures such as muscle and bone against trauma

Question 3

Which is the primary collagen of the dermis, how is it organized?

Answer 3

type I collagen is primary collagen of the dermis, each subtype has 3 polypeptide a-chhains which wrap into one triple helix

Question 4

What is the clinical presentation of Ehlers-Danlos Syndrome?

Answer 4

hyper extensible skin and joints while the skin still retains normal elasticity with skin fragility, caused by mutations in collagen fibers, classic fish mouth scars (genetic disease causes mutations in post-translational modifications of collagen)

NOTE type IV may also involve blood vessels and lead to bruising or gastrointestinal and arterial rupture

No treatment, just minimize trauma

Question 5

What is the clinical presentation of pseudoxanthoma easticum?

Answer 5

yellow papules of neck and axiallae and decreased visual acuity, clumping of elastic fibers affecting the skin, eyes and cardiovascular system (caudication, hypertension, angina or MI) caused by autosomal dominant recessive disease of elastin

Question 6

What is the clinical presentation of Marfan Syndrome?

Answer 6

tall stature, long limbs and digits, scoliosis and flexible joints stretch marks, aortic dilation, and myopia and dystopia lentis or detached retina (caused by autosomal dominant mutation in fibrillin which impairs the structural integrity of skeletal, ocular and CV systems)

Question 7

Describe the arrangement of cutaneous vasculature.

Answer 7

anastomosing “net-like” vascular plexus at three levels (superficial, deep dermal and fascial

Question 8

What is the clinical presentation and causes of livedo reticularis?

Answer 8

reticulate macular erythema that accentuates with cold weather, arising from hypo perfusion of medium-sized vessels, may be associated with autoimmunidiseases or coagulation disorders

Question 9

What is the clinical presentation and causes of vaculitis?

Answer 9

presentation varies with the caliber of vessel affected, cutaneous presents with palpable purpura, necrotizing libedo reticular is and ulcerations; systemic with weight loss, fever, headache and a TON of other random symptoms

both are due to inflammation of the blood vessels

Question 10

What is the clinical presentation of leukocytoclastic vaculitits?

Answer 10

common on legs, specifically a reactive inflammation of the small cutaneuous vessels resulting in palpable purport that is triggered by medication, infection, connective tissue disease or autoimmune disease

NOTE may affect renal vasculature

Question 11

What is the characteristic presentation of morphea (type of scleroderma)?

Answer 11

expanding erythematous plaque that progressively becomes indurated, and the central portion becomes hypo pigmented, surrounded by a lilac colored ring; inactive lesions typically hyper pigmented

Question 12

What symptoms would you expect with limited vs. diffuse scleroderma?

Answer 12

limited would affect mostly the face and distal extremities, presenting with tight thickened skin, Raynaud’s phenomenon ***CREST syndrome

diffuse scleroderma involves the trunk and proximal extremities with cutaneous fibrosis, Rynaud’s phenomenon and additional systemic considerations like pulmonary fibrosis, renal insufficiency and cardiac disease

Question 13

Describe phototaging, what it looks like and what causes these changes.

Answer 13

repeated, prolonged ultraviolet radiation causes skin thinning, large freckles, wrinkles, dilated pores and yellow quality to skin because UV light induces thinning of collagen in skin

Question 14

What are the 3 phases of wound healing?

Answer 14

inflammatory, proliferative, and maturation

Question 15

Why do dermal wounds lead to scarring?

Answer 15

depth of wound casuses dermal collagen to be deposited, while the elastin is not well replaced; the strength of a scar is 20% of final strength 3 weeks post injury and final strength is 70-80% of intact skin.

Question 16

Describe a keloid.

Answer 16

a firm scar extending beyond the borders of the wound which may be caused by injury or inflammatory processes, including acne; excision typically causes a larger keloid then first existed

Question 17

Compare erosions and ulcers.

Answer 17

erosions affect only the epidermis while ulcers effect the epidermis and dermis; partial thickness wounds is injury to the epidermis and superficial dermis, full thickness involves the deep dermis, resulting loss f adnexal structures that contract during the healing process

Question 18

Name 6 factors that might contribute to delayed wound healing.

Answer 18

vascular insufficiency, tissue edema, infection (biofilm) dry wound bed, excessive granulation tissue or chronic radiation injury (destroys skin tissue)

Question 19

Describe panniculitis.

Answer 19

an inflammatory disorder of the fibrous septa between fat lobules

Question 20

What are the clinical findings of erythema nodosum?

Answer 20

a type of panniculitis, casuses tender, erythematous nodules with ill-defined borders reflecting the deep level of the inflammation which can be triggered by infection (strep common), medications (also sarcoidosis, IBD or idiopathic); treatment involves addressing the trigger, rest, elevation, NSAIDS

drugs that are likely to cause erythema nodosum: contraceptive pills

Question 21

What is a pyrogenic granuloma?

Answer 21

rapidly growing, friable vascular lesion that bleeds easily and often arises in sites of trauma which real to reepithelialize unless the lesion is cauterized or surgically removed