Skin Diseases Flashcards
What are the layers of the skin
epidermis
dermis
hypodermis
What cells are in the epidermis
Keratinocytes
merkel cells (pressure receptors)
melanocytes
Langerhans
Tcells
Whats found in the dermis layer
connective tissues
collagen elastin and fibrillin
Blood vessels, sweat glands, hair follicles, sebaceous glands, nerves
What is the hypodermis for?
subcutaneous tissue
Thermal insulator
Energy store
mechanical protector
How does the skin microbial communities prevent disease?
Takes up space and produces AMP
Strengthens epidermal barrier
Primes APCs for adaptive immunity
What are the stages of healing?
Bleeding (clot)
Inflammatory (scab formed, fibroblasts and macrophages produced)
Proliferative (fibroblasts proliferate and subcut. heals)
Remodelling (dermis and epidermis heals)
What mediators are used for tissue remodelling
Fibroblasts, MMPs TGFb
Lymphocytes also involved
What is the role of haemostasis during a skin injury
Injured vessels contract
Coagulation cascade
Platelet aggregation
cytokines which attract fibroblasts and macrophages
Serotonin -> incre. vascular permeability
What becomes macrophages in the late inflammatory stage
Blood monocytes
What happens during the proliferative phase of a wound
Fibroblast migration
Collagen synthesis
Angiogenesis
Granulation tissue formation
Epithelialisation
What happens during the remodelling phase of a wound
Fibronectin and HA (hyaluronic acid) broken down
Collagen bundles strengthen (80% of original)
Collagen synthesis and breakdown by TGFb and MMPs
Scar results
What happens during the early inflammation phase of a wound
complement system activated
Neutrophils
What is eczema
dry irritated inflamed skin
Itching / burning
What are the types of eczema
Atopic
Contact
Seborrhoeic
dyshidrotic
What is atopic dermatitis
*symptoms
*Pharmacology
*prevention of flares
*treatments
*symptoms- dry skin, itchy esp. at night usually occurs w asthma or hayfever
*Pharmacology- defect in skin barrier repair mechanism - filaggrin gene
allergen = Th2 cells = IL4 activates Bcells causing IgE-> mediators for inflammation = mast cell stimulation
*prevention of flares- moisturisers, avoid triggers, mild soap
*treatments- emollients, corticosteroids, phototherapy, topical calcineurin inhibitors
What is contact dermatitis
*symptoms
*prevention of flares
*treatments
*symptoms - 2 types irritant and allergic
*prevention of flares/ treatments- avoid irritants and allergens, emollients, corticosteroids
What is seborrhoeic dermatitis
*symptoms
*Pharmacology
*prevention of flares
*treatments
*symptoms- skin flakes, greasy looking white or yellow scale
Dandruff on scalp
*Pharmacology- overgrowth of yeast
*prevention of flares - stress?
*treatments - children- emollients, topical steroids and antifungals
- adults - ketoconazole, steroid lotions, corticosteroids
What is dyshidrotic dermatitis
Usually with atopic
Hands and feet
Itchy blisters
Emollients, steroids, antibiotics, phototherapy
What is psoriasis
Autoimmune inflammatory skin disease
Normal skin cells produced faster than shed = itchy plaques- white scales
What is plaque psoriasis
Red itchy sore plaques with silvery scales anywhere
What is the treatment for psoriasis
Moisturisers and emollients
Vit D derivatives
Steroids topical (eumovate etc)
Calcineurin inhibitors
Phototherapy
Immunosupressants
Vit A derivatives
Biologics
What is psoriatic Arthritis and how is it treated
Inflammatory join disease affecting joints and tendons
Worse in morning ease with exercise
Treated with:
Painkillers/ NSAIDs
Corticosteroids
DMARDs- leflunomide
Biologics
What are the signs of skin cancer
Asymmetry
Border is irregular
Colour variation
Diameter more than 6mm
Evolving-change
What causes warts and verrucas
HPV causes keratin production on epidermis
Can treat with cryosurgery or salicylic acid creams
