Scar-Reducing and Skin Bleaching Products Study Notes

Definitions and Characteristics of Scars

Definition of a Scar: A scar is defined as a mark remaining in the skin after a wound or ulcer has healed.
Types of Scars: * Flat, Pale Scars: This is the most common type of scar. It results from the body’s natural healing process. Initially, after the wound heals, these scars may appear red, dark, and raised, but they naturally become flatter and paler over time. * Hypertrophic Scars (HS): * Characterized as raised overgrowths of scar tissue at the site of skin injury. * Pathophysiology: Caused by an imbalance in collagen production during the healing process. * Development: They enlarge within the confines of the original wound and tend to improve over time. * Keloid Scars (K): * Similar to hypertrophic scars, these are raised overgrowths of tissue. * Development: Unlike HS, keloids continue to enlarge beyond the original size and shape of the wound. They can grow indefinitely. * Symptoms: They may be itchy or painful and rarely improve in appearance over time. * Causes of injury leading to HS and K include trauma, surgery, blisters, vaccinations, and body piercings. * Acne Scars: These must be distinguished from temporary skin changes: * Macules: Flat, red or reddish spots remaining after an inflamed acne lesion flattens. These typically disappear within $6 \text{ months}$ . * Post-inflammatory Pigmentation: Discoloration at the site of a healed or healing acne lesion; may persist for up to $18 \text{ months}$ . * Sub-types of Acne Scars: * Rolling Scars: Broad depressions featuring a sloping edge. * Boxcar Scars: Broad depressions with sharply defined, steep edges. * Ice-pick Scars: Narrow, deep, and pitted scars. * Keloids: Raised thickened tissue caused by increased tissue formation. * Sunken Scars: These are recessed into the skin. Common causes include chickenpox and ice-pick acne scars. * Stretched Scars: * Occur when the skin around a healing wound is placed under tension. * Commonly found near joints where the skin is stretched during movement. * Can also result from poor healing related to general ill health or malnutrition. * While they may appear normal initially, they can widen and thin over time.

Clinical Management and Therapeutic Factors for Scars

Factors Affecting Therapy Selection: * Family history. * Predisposing and causative factors. * The age of the scar. * The type of scar. * Anatomic location of the scar.
Treatment Rules of Thumb: * For normal scarring, various OTC products can be recommended as options. * For severe scarring, the patient must be referred to a physician.

Scar-Reducing Product Profiles

Onion Extract / Allantoin Gel (Mederma): * Mechanism of Action: Reduces the formation of the scar matrix, reduces inflammation, and inhibits the proliferation of fibroblast cells. * Application Protocol: * Massage into the skin $3 - 4 \text{ times daily}$ . * New Scars: Apply daily for $8 \text{ weeks}$ after the wound has healed. * Existing Scars: Apply daily for up to $6 \text{ months}$ .
Silicone Gel Sheets (Cica-Care™): * Description: A self-adhesive silicone gel layer. * Indications: Management of hypertrophic and keloid scars (both old and new), reducing size/redness, and prevention of new scar formation. * Mechanism of Action: The sheet covers the skin to retain moisture and hydrate the scar tissue. This reduces blood supply and collagen deposition, ultimately making the scar tissue paler and flatter. * Documented Effects: Flattens raised scars, softens and fades red/raised scars, and relieves associated itching and discomfort. * Case Example: A $2\text{-year-old}$ child with scattered hypertrophic scarring from a hot water spillage showed significant improvement after $4.5 \text{ months}$ of Cica-Care™ treatment. * Application Steps: 1. Wash hands; clean the scar and surrounding skin with mild soap; rinse with warm water and dry thoroughly. 2. Cut the sheet to fit the scar size, allowing for a small overlap onto surrounding skin. 3. Apply the adhesive side to the scar without stretching. A light bandage may be used if necessary. * Wearing Schedule (Acclimatization): * Days 1–2: Wear for $4 \text{ hours per day}$ . * Days 3–4: Wear for $8 \text{ hours per day}$ . * Subsequent Days: Increase wear time by $2 \text{ hours per day}$ until a minimum of $12 \text{ hours per day}$ is reached. Ideally, wear for $24 \text{ hours per day}$ . * Maintenance: Wash the sheet, scar, and skin at least twice daily with mild soap. Replace the sheet when it wears out or becomes difficult to clean (usually every $14 - 28 \text{ days}$ ). * Expected Results: Best results are seen after $2 - 4 \text{ months}$ of use. * Precautions: Use only on intact skin. Rashes may develop due to poor hygiene or tight application; if this occurs, reduce treatment to $12 \text{ hours}$ on and $12 \text{ hours}$ off. Discontinue and consult a doctor if the rash persists.
Centella Asiatica Extract (Centellase Cream): * Mechanism of Action: Decreases inflammation, modulates/slows excessive collagen production, and improves wound repair. * Usage: Apply once or twice daily to the affected area.
Vitamin E: * Forms: Creams, oils, and oil capsules (e.g., Kordel’s Natural Vitamin E $200 \text{ IU}$ , Jamieson Vitamin E $30,000 \text{ IU}$ ). * Efficacy Controversy: There is no consistent evidence that Vitamin E improves the long-term appearance of scars. While some reports suggest it speeds healing, clinical studies show no benefit to cosmetic outcomes after skin surgery. In $90\%$ of cases, topical Vitamin E either had no effect or actually worsened the cosmetic appearance of scars.

Causes and Mechanisms of Skin Discolouration

Hyperpigmentation Causes: Uneven skin tone results from various factors including old acne, bug bites, skin trauma, underarm irritation, sun damage (freckles), and Melasma (hormonal causes).
Process: Discoloration involves epidermal hyperpigmentation due to melanin production.

Skin Bleaching Agents and Pharmacology

Hydroquinone: * Mechanism of Action: Inhibits the enzyme tyrosinase, which interferes with melanin production. It also causes damage to melanocytes and melanosomes. * Concentrations: Available in $2 - 4 \%$ . * Adverse Effects: Risk of Ochronosis (bluish-black pigmentation) and potential cancer-causing properties.
Arbutin: * Source: Extracted from the bearberry plant. * Mechanism of Action: Functions as a tyrosinase inhibitor to prevent melanin formation. * Advantages: Less irritating than other agents; better suited for sensitive skin.
Kojic Acid and Licorice Extract: * Mechanism of Action: Both act as tyrosinase inhibitors to prevent the formation of melanin.

Clinical Counseling for Skin Bleaching Products

Targeted Application: Products should only be applied to dark spots, avoiding the surrounding normal skin.
Product Selection: If there is no well-defined area of discoloration, botanical-based ingredients (e.g., Kojic acid) are preferred over hydroquinone.
Usage Duration: Apply to the affected area twice daily. Discontinue application once desired effects are achieved.
Sun Protection: Sun protection is vital during treatment. Patients must use a sunscreen with a minimum of $SPF \, 15$ .