Skin disorders

Skin Anatomy

• Skin:

  • The body’s outer layer and the largest organ.

  • Thickness: Approximately 2 mm.

  • Weight: Between 3.5 kg and 10 kg (around 8% of total body mass).

  • Surface area: Ranges from 1.5 to 2 square meters.

Layers of Skin

• Epidermis:

  • Functions as a waterproof barrier and establishes skin tone.

• Dermis:

  • Composed of tough connective tissue, providing strength and resilience.

  • Contains hair follicles and sweat glands.

• Hypodermis / Subcutis / Subcutaneous Layer:

  • Comprised of fat and connective tissue, also known as panniculus adiposus.

  • Functions: Cushions the skin, insulates the body from cold temperatures, and stores nutrients and energy.

Skin Disorders

• Tanning:

  • Melanocytes remain in place, but their melanin moves leading to skin tanning.

• Common Issues:

  • Disorders characterized by color changes or raised lesions on the skin surface.

  • Dry skin: Often results in cracks.

  • Skin disorders may be differentiated according to size and layers of skin affected.

  • Frequent need for medical referral may arise.

  • Peeling after sun exposure indicates epidermal quality control.

Disorders of Skin Pigmentation

• Hyperpigmentation: Excessive melanin production.

• Hypopigmentation: Reduced melanin production.

• Albinism: Genetic condition resulting in reduced melanin synthesis.

• Chloasma: Also called the mask of pregnancy; involves tanned skin patches.

• Lentigines: Commonly known as freckles, localized areas of hyperpigmentation.

• Leukoderma: Melanin loss localized at specific skin sites.

• Nevus: Moles formed through the accumulation of melanocytes.

Anatomy of the Skin

• Epidermis:

  • Contains viable epidermis and dividing keratinocytes leading to mature, flattened corneocytes (10-30 layers with lipid bilayers).

• Dermis:

  • Composed of fibroblasts, collagen, elastin, and immune cells (macrophages).

  • Important for infection control and providing structural support via nerves, blood vessels, and lymphatics.

  • Pilosabaceous units consist of hair shaft, hair follicle, sebaceous gland, and erector pili muscle.

• Subdermis:

  • Connective tissue with varying adipose content; provides blood supply to the skin.

Skin Lesions

• Bulla:

  • A blister containing watery fluid, larger than a vesicle; requires medical referral.

• Cyst:

  • An abnormally developed sac containing fluid or morbid material; requires medical referral.

• Macule:

  • A flat, small spot or discoloration of the skin.

• Nodule:

  • A solid bump larger than 0.4 inches (1 cm), easily felt; requires medical referral.

• Papule:

  • A pimple.

• Pustule:

  • A raised, inflamed pimple.

• Tumor:

  • An abnormal mass of cells.

• Crust:

  • Dead cells form over a wound or blemish during healing.

• Fissure:

  • A crack in the skin.

• Ulcer:

  • An open lesion that may contain pus.

Disorders of the Sebaceous (Oil) Glands

• Sebaceous glands produce oils, contributing to skin shine.

• Common Conditions:

  • Comedones: Open or closed comedones create a rough skin texture.

  • Milia: Keratin-filled cysts.

  • Acne: Common pimples.

  • Sebaceous cyst: Large lesions filled with sebum.

  • Seborrheic dermatitis: Inflammation of sebaceous glands.

  • Rosacea: Chronic inflammation leading to congestion primarily on cheeks and nose.

Inflammations and Common Infections of the Skin

• Conjunctivitis: Pinkeye, inflammation of the conjunctiva.

• Dermatitis: A general inflammatory skin condition.

• Eczema: May present as acute or chronic lesions (dry or moist).

• Herpes Simplex: Leads to fever blisters.

• Impetigo: Presents with weeping lesions.

• Psoriasis: A common chronic inflammatory skin disease characterized by red, scaly patches.

Hypertrophies of the Skin

• Keratoma: A callus formed due to skin thickening.

• Mole: A small brownish spot or blemish.

• Skin tag: A small brown or flesh-colored outgrowth.

• Verruca: A wart, resulting from viral infection.

Skin Cancer

• Basal Cell Carcinoma: Originates from the bottom layer of the epidermis.

• Squamous Cell Carcinoma: Originates from the top layer of the epidermis.

• Malignant Melanoma: Characterized by abnormal pigmentation and color variations.

Causes of Skin Disorders

• Microorganisms: Bacteria, fungi, parasites, or viruses may become trapped in skin pores.

• Weakened immune system: Increases susceptibility to skin disorders.

• Environmental Factors: Direct contact with allergens or irritants, or infected skin from another person.

• Genetic Factors: Inherited predisposition can contribute to skin conditions.

Treatment Options for Skin Disorders

• Antibiotics: Used to treat bacterial infections.

• Antihistamines: Useful for treating allergic reactions.

• Laser Skin Resurfacing: A cosmetic procedure for skin rejuvenation.

• Medicated Creams, Ointments or Gels: Topical treatments for various conditions.

• Moisturizers: Used to retain skin moisture.

• Oral Medications: Systemic treatment options may be necessary.

• Steroid Pills, Creams or Injections: Used to reduce inflammation.

• Surgical Procedures: When necessary for removal of lesions or damaged skin.

Examination of Acne and Problem Skin

• Acne Prevalence: Affects various age groups, commonly teenagers and young adults.

• Retention Hyperkeratosis: Genetic tendency for acne-prone skin leads to retention of dead cells in hair follicles.

• Propionibacterium (Cutibacterium) Acne: Bacteria that thrive in the anaerobic environment of blocked pores, leading to acne.

• Papulopustular Acne: Characterized by inflammatory red bumps or pus-filled lesions.

Acne Treatment

• Cleansers and Toners for Oily Skin: Essential for cleaning the skin of excess oils.

• Follicle Exfoliants: Promote shedding of dead skin cells to keep follicles clear.

• Avoidance of Fatty Skin-Care Products: Helps prevent exacerbation of acne.

• Light Moisturizer: Recommended for hydration without clogging pores.

Aging Skin Issues

• Intrinsic Factors:

  • Factors such as genetics, ethnicity, gravity, and facial expressions lead to natural aging.

• Extrinsic Factors:

  • Environmental influences include sun exposure, smoking, alcohol overuse, stress, poor nutrition, and pollution exposure.

Sun and Its Effects

• Up to 80-85% of skin aging is attributed to UV radiation.

• UVA Rays: Weaken collagen and elastin fibers.

• UVB Rays: Cause sunburn and affect melanocytes leading to tanning.

Protection from the Sun

• Avoid deliberate exposure and prolonged sun exposure.

• Apply sunscreen liberally to protect skin.

• Restrict sun exposure for children under six months.

• Wear hats and protective clothing when outdoors.

Conditions and Their Appearances