Sunburn: Pathology, Causes, and Management

Medical Lecture: Sunburn

Introduction

Sunburn is a radiation burn of living tissue caused by excessive exposure to ultraviolet (UV) radiation. Even brief exposure to high UV levels can result in skin damage, making sunburn a significant public health concern due to its acute effects and long-term complications.

Pathology

• Mechanism of UV Damage:
• Direct DNA Damage: Formation of thymine dimers → activation of DNA repair mechanisms → inflammation and apoptosis.
• Mast Cell Activation: Mast cells degranulate → release histamine, serotonin, and TNF → prostaglandin and leukotriene synthesis → inflammation.
• Melanin Production: UV exposure stimulates melanin production, providing photoprotection.

Risk Factors

• Environmental Factors: Outdoor activities during peak sun hours or high UV radiation areas.
• Susceptible Groups: Fair-skinned individuals, infants, elderly, and those with genetic DNA repair defects.
• Photosensitizing Medications: Drugs like antibiotics and diuretics that increase UV sensitivity.

Clinical Presentation

1. Signs and Symptoms:
• Erythema and warmth due to vasodilation.
• Blistering, swelling, and edema in moderate to severe cases.
• Systemic symptoms such as fever, chills, and dehydration.
2. Classification:
• Superficial (First-degree): Red, erythematous skin involving the epidermis only.
• Superficial Partial Thickness (Second-degree): Extends to the dermis with blister formation.

Complications

1. Short-Term: Increased risk of secondary infections due to compromised skin barrier.
2. Long-Term: Higher risk of developing skin cancers, including melanoma, basal-cell carcinoma, and squamous-cell carcinoma.

Management

• Medications: Topical hydrocortisone for localized inflammation and NSAIDs for pain relief.
• Non-Medical Interventions: Cool baths, skin moisturizers, and protective clothing.
• Prevention:
• Behavioral Modifications: Avoid UV exposure during peak hours (10:00 AM – 4:00 PM).
• Sunscreen: Apply SPF 30 or higher, reapplying every 2 hours or after swimming/sweating.

Key Takeaways

Sunburn is preventable with proper sun protection. Early intervention minimizes complications, while long-term vigilance reduces the risk of UV-induced skin cancers.

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