Skin Pathophysiology and Cancer Overview

Created by

@AttentiveEarth

Study Notes

Acne: Inflammation of sebaceous glands, leading to clogged pores.
Dermatitis: Inflammation of the skin, primarily affecting the papillary layer of the dermis, causing itching and redness.
Eczema: Skin lesions caused by an allergy (commonly a rash), characterized by itchiness, redness, and potential thickening and darkening of the skin.
Psoriasis: An immune system disorder causing hyperproliferation and abnormal differentiation of epidermal cells, resulting in reddish plaques with a silvery covering.
Rosacea: Enlarged facial skin blood vessels, leading to a reddened face.
Tinea: Fungal skin infections.

Skin Cancer: A common cancer, primarily caused by UV radiation, damaging epidermal cells. Epidermal cells may have genes that lead to cancer development.
Types of Skin Cancer (Epidermal):
- Squamous Cell Carcinoma: Originates from keratinocytes in the stratum spinosum, can metastasize (spread).
- Basal Cell Carcinoma: Originates from cells in the stratum basale, the most common type, rarely metastasizes.
- Melanoma: Originates from melanocytes, if not detected promptly it can quickly spread.

ABCD Method for Melanoma Detection:
- A: Asymmetry: One side of the mole looks different from the other.
- B: Border: Irregular or uneven borders.
- C: Color: A mixture of colors (tan, brown, black, red).
- D: Diameter: Greater than 6mm in size.

Burns: Result from exposure to heat, friction, radiation, electrical shock, or chemicals.
Categorization: Burns are classified according to the depth of tissue involvement:
- Superficial: Dry, red, easily blanching skin, sometimes painful, like a sunburn.
- Superficial Partial Thickness: Moist, red, blanching skin, blisters; very painful.
- Deep Partial Thickness: Drier, more pale, less blanching, less painful.
- Full Thickness: Dry, leathery texture, variable color (white, brown, black). Loss of pin prick sensation
Severe Burn Complications: The loss of skin function can result in water, electrolyte, and metabolic disturbances. The significant loss of skin can lead to widespread infections.

Water and Electrolyte Imbalance: Damage to the skin barrier affects water and electrolyte balance, potentially leading to a loss of plasma proteins.
Temperature Regulation: Significant losses of water lead to evaporative cooling.
Infection: Moisture and barrier damage increase risk of bacterial growth, leading to widespread infection.

Fluid Replacement: Essential to restore fluids and electrolytes.
Nutrient Support: Meeting increased metabolic demands.
Infection Prevention: Removal of infected tissue and cleaning of burn coverings.

Full-thickness burns: Require grafts to promote healing as there's no viable skin to develop new tissue from.

Skin as a Drug Delivery System: Can deliver drugs to specific areas or into the bloodstream.
Factors affecting drug delivery: Factors like molecular weight, solubility, and partitioning coefficients are key for efficient transport.
Methods of delivery:
- Transappendageal: Through hair follicles or sweat glands.
- Transepidermal: Intercellular or transcellular (between and through epidermal cells).