Dermis and Subcutaneous Tissue Flashcards
What cell types do you find in the dermal layer?
dendrocytes, macrophages, fibroblasts, and mast cells
What is the primary type of collagen in the dermis?
Type 1
What are the features of Type I Ehlers-Danlos syndrome?
hypermobility of joints
excessive stretch to skin
fragile skin
atrophic (‘fish mouth’) scars
Ehlers-Danlos is caused by mutations in what structural component of the dermis?
collagen
What are features of Type IV Ehlers-Danlos syndrome?
involve blood vessels and leads to bruising, GI, and arterial rupture
What are common features of - Pseudoxanthoma elasticum (PXE)?
Autosomal recessive
Affects eye, skin, and CV system
Yellow papules of the lateral neck and axillae
Ocular involvement that affects visual acuity and may lead to blindness
CV complications like hypertension, angina and MI
onset in 1st or 2nd decade of life
Marfan syndrome is caused by a genetic disorder of what?
fibrillin
What are the common features of Livedo reticularis?
reticulated macular erythema of the skin
most common in the lower extremities
Hypoperfusion of the skin –> mostly due to cold
What are some of the common features of Leukocytoclastic Vasculitis
Inflammation of blood vessels
Caused by medications, infection, and autoimmune diseases
present with palpable purpura
legs and ankles are most often affected
What is palpable purpura?
reddish-purple, domed papules that do not blanch with presure
What are the 3 phases of normal wound healing?
Inflammatory, proliferative and maturation
During what phase of the wound healing response is there an influx of neutrophils and macrophages?
Inflammatory
Excess collagen deposits result in ______.
a keloid
What is a pyogenic granuloma?
a rapidly growing, friable vascular lesion that bleeds easily and often arises in sites of trauma.
What is the treatment of a pyogenic granuloma?
Cauterization or surgical removal
What is sclerosis?
hypocellular thickening of collagen
What are common features of morphea (localized) scleroderma?
expanding erythematous plaque that progressively become indurated
central point becomes hypopigmented and surrounded by a lilac-colored ring
trunk is commonly involved
What are common features of systemic sclerosis?
Raynaud’s pehnomenon
may be associated with CREST
What is Raynaud’s phenomenon?
episodic color changes in the fingers and toes in response to cold
What is CREST syndrome?
Calcinosis cutis (Ca deposits in the skin) Raynaud's phenomenon Esophageal dysmotility Sclerodactyly (induration of the digits) Telangiectasis
What are common features of diffuse scleroderma?
Involves the trunk and proximal extremities
Cutaneous fibrosis, Raynaud’s phenomenon, pulmonary fibrosis, renal insufficiency and cardiac disease may occur
What are some side effects of photoaging?
Atrophy, lentigines (large freckles), rhytides (wrinkles), dilated pores, and a yellow quality to the skin
What causes the yellow color seen in photoaged skin?
fractured/degenerated elastic fibers
What is Poikiloderma of Civatte?
telangiectasias, hyperpigmentation, hypopigmentation , and atrophy
What is actinic purpura?
focal bleeding caused by UV induced thinning of collagen
What areas do not have subcutaneous tissue?
eyelids and male genitals
What is Panniculitis?
an inflammatory disorder of the subcutaneous fat (lobules or fibrous septae)
What are some common features of Panniculitis?
tender (i.e painful), erythematous, non-ulcerated nodules with ill-defined borders
occurs most often on the lower extremities
What is Erythema Nodosum (EN)?
most common type of panniculitis
caused by medications (CONTRACEPTIVES), infections, sarcoidosis, IBD, and idopathic causes
Wounds are at 20% final strength ______ after injury
3 weeks
The final strength of a scar is _______ that of intact skin
70-80%
What is a hypertrophic scar?
When the scar is thick and raised and composed mostly of collagen, but within the borders of the injury (normal)
