Skin Disorders Overview

Importance of Skin Disorders

  • Interface Role: Serves as the boundary between internal organs and the external environment.
  • Factors Influencing Disorders: Caused by various elements, including:
    • Sun exposure
    • Parasites
    • Viruses
    • Bacteria
    • Genetic factors
    • Circulation issues
  • Prevalence: Affect 30-70% of individuals across all cultures and ages.

Structure & Function of Skin

  • Largest Organ: Covers about 1.5-2 square meters.
  • Protective Functions:
    • Shields against physical injury, UV rays, and microorganisms.
    • Prevents fluid loss from internal organs.
    • Regulates body temperature.
    • Receives external sensory signals.
    • Synthesizes Vitamin D.

Skin Layers

  • Epidermis: Outermost layer of the skin.
  • Dermis: Connective tissue layer beneath the epidermis; separates epidermis from subcutaneous tissue.

Cell Types in Skin

  • Keratinocytes: Main epidermal cells that produce keratin for protection and may aid in immune response.
  • Melanocytes: Produce melanin for pigment and UV protection.
  • Sebaceous Glands: Found in the dermis, secrete sebum to lubricate skin and hair.

Manifestations of Skin Disorders

Lesions & Rashes
  • Lesion: Loss of normal tissue continuity or structure, can manifest as lumps, ulcers, or colored areas (like moles).
  • Rash: General term for skin eruptions from conditions like chickenpox, heat rashes, or drug reactions.
  • Factors to Consider:
    • Location/Distribution
    • Color
    • Configuration
    • Texture
    • Morphology
Pigmentary Disorders
  • Albinism: Complete/partial absence of melanin; characteristics include pale skin, white hair, light eyes, ocular issues, and higher sunburn risk.
  • Vitiligo: White patches on skin due to dying melanocytes; may be autoimmune; treatments include cosmetic measures.
  • Melasma: Dark patches on face, exacerbated by sun exposure, usually treated with sunscreens and bleaching agents.
Pruritus (Itching)
  • Description: Unpleasant sensation leading to scratching; severity can disrupt life.
  • Factors: Causes include skin inflammation and external stimuli.
  • Treatments: Aim to relieve itch sensation and prevent complications (e.g., anti-histamines, topical agents).
Dry Skin
  • Characteristics: Rough, scaly, and lined skin caused by dehydration or underlying disorders.
  • Consequences: Severe itching; scratching can lead to skin damage.
  • Treatments: Moisturizers and changes in soaps.

Primary Skin Disorders

  • Definition: Dermatologic conditions with lesions.
  • Types:
    1. Infectious Processes
    2. Pustular Disorders
    3. Allergic & Hypersensitivity Dermatoses
    4. Papulosquamous Dermatoses
Infectious Processes
  • Caused by: Fungi, bacteria, or viruses.
  • Fungal Infections: Tinea (Ringworm); characterized by pruritus, diagnosed via skin scrapings; treated with antifungal agents.
  • Bacterial Infections:
    • Impetigo: Superficial infection with vesicles or pustules; common in children.
    • Cellulitis: Deeper infection leading to redness, swelling, and pain.
  • Viral Infections: Warts from HPV, characterized by irregular epidermal thickenings; treatment may include removal.
Pustular Disorders
  • Examples: Acne vulgaris, characterized by inflammatory lesions; treatments focus on skincare and medication.
Allergic & Hypersensitivity Dermatoses
  • Types: Atopic dermatitis (eczema) and contact dermatitis; characterized by inflammatory responses.
  • Treatments: Targeting dryness and itch, avoiding irritants, and using moisturizers.
Papulosquamous Dermatoses
  • Example: Psoriasis, a chronic inflammatory condition with thickened skin and plaques; treatments aim to reduce symptoms and inflammation.

UV Radiation and Skin Cancer

  • Effects: Sunburn causes short-term skin damage; repeated exposure increases risk for skin cancer.
  • Types of Skin Cancer:
    • Nonmelanomas: Basal cell carcinoma and squamous cell carcinoma; usually treatable when detected early.
    • Malignant Melanomas: Most dangerous; risk factors include blistering sunburns; early detection is critical (ABCDE method for moles).
    • Treatment: Surgical removal and clinical follow-up.

Thermal Injury (Burns)

  • Types:
    • 1st Degree: Red, dry, painful skin; heals within a week.
    • 2nd Degree: Red with blisters; heals within 2-3 weeks.
    • 3rd Degree: Dry, leathery; requires excision.
    • 4th Degree: Extends to muscle/bone, painless; requires serious interventions.
  • Management: Depends on severity, may require fluid resuscitation and meticulous wound care.

Learning Objectives

  • Understand skin cell types and their roles in disorders.
  • Identify skin disorders by characteristics and treatment methods.
  • Recognize UV radiation's skin impact and burn classifications.
  • Visualize lesions through images to aid in distinguishing disorders.