dermatology

Question 1

what causes a defective skin barrier

Answer 1

• Loss of NMF leads to dry skin and the development of cracks
• An abnormal lipid bilayer provides an inadequate permeability barrier
• Inflammation in the skin can directly cause depression by affecting the brain
• Systemic disease

Question 2

describe the healthy skin barrier

Answer 2

filaggrin produces natural moisturising factor (NMF) - helps maintain moisture + acidic environment
desquamination - corneocytes shed from surface of stratum corneum
lipid lamellae keeps the water inside the skin cells

Question 3

what is the normal pH of the skin?

Answer 3

5.5

Question 4

what causes skin flare ups

Answer 4

Causes by allergens which are able to penetrate the skin, they are met with lymphocytes which release chemicals that induce inflammation
• Red skin: dilation of blood vessels due to lymphocyte activity
• Itchy skin: stimulation of nerves
• Dry skin: skin cells leaking due to lymphocyte activity

Question 5

what is the effect of increased pH on the skin

Answer 5

• If profilaggrin and thus filaggrin are not present for any reason, there will be a lack of NMF meaning there will be less water retention in the corneocytes
• This means that pH will increase – resulting in damage to the skin barrier since the corneodesmosomes become damaged. increasing the risk of infection

Question 6

hoe does acne arise

Answer 6

• In acne, hypercornification of the stratum corneum occurs resulting in adherent cells blocking the entrance to hair follicles
• This results in the increased production of sebum – causing the skin to feel greasy – eventually some sebum gets trapped in the narrowed hair follicle – stagnates
• Provides anaerobic conditions which allow the propionic bacteria acnes to multiply
• The p.acnes breakdown the triglycerides in sebum into fatty acids resulting in irritation and inflammation and the attraction of neutrophils – puss formation