Sunburn: Symptoms, Types, Causes and Treatment

Sunburn is more than just an uncomfortable inconvenience after a sunny day outdoors. It’s a complex biological reaction to ultraviolet (UV) radiation, with consequences that go beyond red skin and peeling. Understanding sunburn—its symptoms, types, causes, and evidence-based treatment options—not only helps manage its immediate discomfort but also reduces long-term risks to skin health. This comprehensive guide explores the science and practical aspects of sunburn, backed by recent research.

Symptoms of Sunburn

Sunburn symptoms are the body’s way of signaling damage caused by excessive UV exposure. These symptoms can range from mild redness to more severe pain and systemic effects, depending on the intensity and duration of sun exposure.

Symptom	Description	Severity Range	Source(s)
Redness	Skin turns pink or red	Mild to severe	1
Heat	Skin feels warm or hot	Mild to severe	1
Pain	Tenderness, sometimes severe	Mild to severe	3
Swelling	Puffy, inflamed skin	Moderate	1
Blistering	Fluid-filled bumps	Moderate/severe	2
Fatigue	Overall feeling of tiredness	Mild	1
Dizziness	Lightheadedness, faintness	Mild	1

Table 1: Key Symptoms

Recognizing Sunburn Symptoms

Sunburn typically starts with redness and a sensation of warmth, usually within a few hours of UV exposure. The skin may feel tender or painful to the touch, with swelling possible in more sensitive individuals or after longer exposure periods 1 3.

Progression of Symptoms

• Early Phase:
  • Redness and heat are the first signs, often appearing 2–6 hours after sun exposure.
  • Mild fatigue or slight dizziness may accompany skin symptoms, especially after prolonged outdoor activity 1.
• Later Phase:
  • Pain intensifies, peaking at 12–24 hours post-exposure.
  • In more severe cases, blisters may form, indicating a second-degree sunburn 2.
  • The affected area may swell and become itchy as the skin begins to heal.

Systemic Effects

While most sunburns are localized to the skin, severe sunburn can cause systemic symptoms:

• Fever
• Chills
• Nausea or headache These signs may indicate a need for medical attention, particularly if accompanied by extensive blistering or dehydration 1.

Types of Sunburn

Sunburn isn’t a one-size-fits-all condition. The severity and nature of a sunburn depend on several factors, including duration of exposure, skin type, and the UV index at the time of exposure. Understanding the types of sunburn can help you assess risk and choose the right management strategy.

Type	Skin Layer Affected	Visual Signs	Source(s)
First-degree	Epidermis (surface)	Redness, mild pain	2
Second-degree	Epidermis + dermis	Blisters, swelling	2
Third-degree	All skin layers	Deep tissue damage	2
Chronic Effects	Skin & eyes	Photoaging, melanoma	2

Table 2: Sunburn Types

First-Degree Sunburn

First-degree sunburn is the most common type. It affects only the outermost layer of the skin (epidermis) and presents as redness, warmth, and mild discomfort. The skin may peel after a few days as it heals 2.

Second-Degree Sunburn

More intense UV exposure can result in second-degree sunburn. Here, both the epidermis and the underlying dermis are damaged. Key features include:

• Blistering
• Increased swelling
• More pronounced pain and tenderness
  Second-degree sunburns pose a higher risk of infection due to breaks in the skin barrier 2.

Third-Degree Sunburn

Rarely, sunburn can extend to all layers of the skin, resulting in third-degree burns. These are medical emergencies, often involving deep tissue injury, white or charred skin, and loss of sensation. Immediate care is essential 2.

Chronic and Long-Term Effects

Repeated sunburns, even if mild, can have long-term consequences:

• Photoaging (premature skin aging)
• Increased risk of melanoma and other skin cancers
• Eye damage and immune system effects
  These chronic effects highlight the importance of sun protection and timely sunburn management 2.

Causes of Sunburn

Understanding the root causes of sunburn is vital for prevention and risk reduction. Sunburn primarily results from overexposure to ultraviolet (UV) radiation, but several factors can influence susceptibility and severity.

Cause	Mechanism/Trigger	Risk Factors	Source(s)
UV Radiation	DNA/tissue damage, inflammation	High UVI, prolonged sun	1 2 3
Skin Type	Pigment (melanin) content	Fair skin, light eyes	2
Duration/Intensity	Time outdoors, peak sun hours	Noon-3 pm, clear skies	2
Cellular Response	TRPV4, endothelin-1 activation	Pain, tissue injury	3

Table 3: Sunburn Causes

The Role of UV Radiation

Sunburn is fundamentally a radiation burn. Ultraviolet B (UVB) rays, in particular, penetrate the skin’s surface and cause cellular damage:

• DNA mutations
• Generation of reactive oxygen species (ROS)
• Inflammatory mediator release
  This triggers the classic symptoms of redness, swelling, and pain 1 3.

Skin Type and Individual Susceptibility

Not all skin reacts the same way to UV exposure. People with fair skin (low melanin), light eyes, and blonde or red hair are more susceptible to sunburn than those with darker skin. The Ultraviolet Index (UVI) helps predict risk based on sunlight intensity and skin type 2.

Duration, Intensity, and Environmental Factors

• Time of Day: UV levels peak between 10 am and 3 pm.
• Location: Higher altitudes and latitudes closer to the equator increase UV risk.
• Weather: Clear skies and reflective surfaces (e.g., water, sand, snow) amplify UV exposure 2.

Cellular and Molecular Mechanisms

UVB exposure activates specific skin cell pathways:

• TRPV4 Ion Channels: Trigger pain and tissue injury after sunburn 3.
• Endothelin-1: A mediator that amplifies pain and inflammation 3. Understanding these pathways opens new avenues for targeted therapies in the future.

Treatment of Sunburn

Treating sunburn focuses on relieving symptoms and supporting skin repair. While there is no “cure” that reverses the cellular damage, several evidence-based strategies can reduce discomfort and promote healing.

Treatment Approach	Effect/Benefit	Limitations	Source(s)
Symptom Relief	Pain, redness reduction	No faster healing	6 7
NSAIDs/Indomethacin	Reduces inflammation	Short-term effect	7
Antioxidants	Decrease skin damage	Preventive mainly	4 8
Vitamin D	Reduces inflammation	High dose needed	5
Emollients/Moisturizers	Skin comfort, barrier	Mostly supportive	6

Table 4: Sunburn Treatments

Symptomatic Management

The mainstay of sunburn treatment is symptom management:

• Cool compresses: Soothe hot, inflamed skin.
• Oral hydration: Replenishes fluids lost through damaged skin.
• Emollients/Moisturizers: Help repair the skin barrier and reduce dryness 6.

Anti-Inflammatory Medications

• NSAIDs (e.g., ibuprofen, naproxen): Help reduce pain and inflammation when taken orally.
• Topical indomethacin: Shown to be particularly effective at reducing redness, warmth, and pain—more so than corticosteroid creams in some studies 7.

Antioxidants and Nutritional Support

• Vitamin C and Vitamin E: Oral supplementation with high doses of these antioxidants has been shown to increase the skin’s resistance to UV-induced damage and reduce the severity of sunburn reactions 4. These nutrients help neutralize ROS and decrease inflammation.
• Polyphenols: Found in foods like green tea, chocolate, and grape seeds, both topical and oral polyphenols may protect against UV-induced skin damage, but more research is needed to confirm their efficacy and optimal dosing 8.

Vitamin D

Emerging research suggests that high-dose vitamin D, taken shortly after sunburn, can attenuate inflammation and promote skin barrier repair. This effect is linked to increased expression of anti-inflammatory mediators such as arginase-1 5.

What Doesn’t Work

Despite widespread use, corticosteroids, antihistamines, and some other topical agents have not shown consistent benefits in reducing recovery time or reversing skin damage after sunburn 6.

When to Seek Medical Help

Seek prompt medical attention if:

• Large or numerous blisters develop
• Symptoms are accompanied by high fever, chills, or confusion
• Signs of dehydration (e.g., persistent vomiting, fainting) occur
• The sunburn covers a significant portion of the body

Conclusion

Sunburn is a common yet potentially serious consequence of excessive UV exposure. Understanding its symptoms, types, causes, and evidence-based treatments empowers individuals to manage sunburn effectively and protect their long-term skin health.

Key Takeaways:

• Sunburn symptoms include redness, warmth, pain, swelling, and, in severe cases, blisters and systemic effects 1 3.
• Sunburn types range from mild (first-degree) to severe (third-degree), with the risk of chronic skin and eye damage from repeated exposure 2.
• The primary cause is overexposure to UV radiation, with risk influenced by skin type, environmental factors, and cellular response 1 2 3.
• Treatment focuses on symptom relief, anti-inflammatory agents, and antioxidants. Topical NSAIDs, oral vitamin D, and vitamins C/E show promise, while corticosteroids are less effective 4 5 6 7.
• Prevention and early management are crucial to minimize both short- and long-term skin damage.

By staying informed and proactive, you can enjoy the sun safely and keep your skin healthy for years to come.