Issues with Integumentary System

Question 1

Eczema (Atopic dermatitis)

Answer 1

Either a primary immune dysfunction with IgE sensitization resulting, causing allergic inflammation and disturbance to the epithelial barrier disturbance, or a primary defect in the epithelial barrier leading to dysfunction of the immune response and inflammation

Question 2

Seborrhoeic dermatitis

Answer 2

Malassezia may cause release of inflammatory free fatty acids and can activate the alternate complement pathway (promoting phagocytic attack of pathogens)

Question 3

Contact dermatitis

Answer 3

May be irritant or allergic

Irritant - release of pro inflammatory cytokines in response to direct chemical damage

Allergic - T-cell mediated inflammation due to repeated exposure to the allergen

Question 4

Urticaria

Answer 4

Release of histamine, bradykinin and other vasoactive substances from mast cells and basophils
Activation of histamine receptors leads to capillary vasodilation and increased capillary permeability.

IgE allergic responses mediated by antigens and cytotoxic T cells

Complement mediated reactions due to infection

Question 5

Psoriasis

Answer 5

Considered to be autoimmune in nature

Epidermis infilitrated by activated T cells triggering excessive proliferation of keratinocytes

Elevated levels of proinflammatory mediators released

More rapid cell turnover rate, vascular dilation in affected areas

Question 6

Acne

Answer 6

Disruption to healthy microflora Anaerobic C. acnes produces proinflammatory mediators triggering inflammation in follicles

Excess sebum production (androgens contribute here)
Hyperkeratinisation of follicles occurs
Development of lesions

Question 7

Rosacea

Answer 7

Increased number of blood vessels with greater blood flow and exaggerated vasodilation with heat
Potentially exposure to harsh climates and extremes of temperature cause damage to cutaneous blood vessels and dermal connective tissue

Question 8

Pityriasis (tinea) versicolor

Answer 8

Malassezia yeast (of which there are fourteen species), a normal component of the cutaneous flora, converts from its commensal form to a parasitic pathogenic form due to the risk factors detailed above

Question 9

Tinea (capitis, corporis and pedis)

Answer 9

Tinea capitis and tinea corporis – ringworm of scalp and body respectively
Tinea pedis – athletes foot
Caused by dermatophytes
Warm, humid conditions favour overgrowth

Dermatophyte fungi make use of keratinase enzymes in the skin to invade the superficial keratin layer (infection does not penetrate more deeply than this) or in the case of T. capitis the hair shaft

Question 10

Melanoma

Answer 10

Moles (benign melanocytic naevi) are possibly precursors of melanoma, degenerating over time with exposure to environmental risk factors to become melanoma