Sunburn Clinical Presentation

Updated: Jun 02, 2017
  • Author: Christopher M McStay, MD; Chief Editor: Joe Alcock, MD, MS  more...
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History and symptoms for sunburn may include the following:

  • Recent sun exposure or outdoor activity; outdoor occupations or hobbies; use of indoor tanning equipment

  • Erythema develops after 3-4 hours and peaks at 12-24 hours. [8]

  • Pain

  • Possible fever, chills, malaise, nausea, or vomiting in severe cases

  • Blistering

  • Erythema that resolves over 4-7 days, usually with skin scaling and peeling [8] (See the image below.)

    Subacute sunburn of shoulder with peeling in a 21- Subacute sunburn of shoulder with peeling in a 21-year-old male.
  • Assess for exposure to photosensitizing drugs. See Medscape Reference article Drug-Induced Photosensitivity for an in-depth discussion and list of common photosensitizing drugs.

  • Assess for heavy alcohol use, which is associated with sunburning. [11, 18]


Physical Examination

Patients at highest risk typically have fair skin, blue eyes, and red or blond hair. [15]

The acute inflammatory response, with the following, is greatest 12-24 hours after exposure [8] :

  • Erythema

  • Warmth

  • Tenderness

  • Edema

  • Blistering (severe cases), a sign of either a superficial partial-thickness or deep partial-thickness (second-degree) burn [20]

Fever can present in severe cases. [8]

UVR may be transmitted through clothing, especially when wet, so sunburn may occur under clothed skin. [21]

Delayed scaling and desquamation occurs 4-7 days after exposure. [8]



Sunburn is caused by excessive exposure of the skin to UVR. The ultraviolet spectrum can be divided into ultraviolet A-I (UVA-I), 340-400 nm; ultraviolet A-II (UVA-II), 320-340 nm, ultraviolet B (UVB), 290-320 nm; and ultraviolet C (UVC), 200-290 nm. [1] Solar UVR of wavelengths shorter than 290 nm are filtered out or absorbed in the outer atmosphere and are not encountered at sea level. [1] Shorter wavelength UVB rays are much more effective at inducing erythema than UVA rays and, therefore, are the principal cause of sunburn. [1] However, UVA comprises the majority of UVR reaching the surface of the earth (about 95-98% at midday) and, therefore, accounts for a significant percentage of the immediate and long-term cutaneous effects of UVR. [1]

The minimal single dose of UVR (energy per unit area) required to produce erythema after 24 hours at an exposed site is known as the minimal erythema dose (MED). This dose differs by skin type. [2]

Multiple factors influence UVR-induced erythema; these are listed below:

  • Wavelength: UVB is more erythemogenic than UVA. [2]

  • Skin type/pigmentation: Compared with type I-II skin, patients with type IV-V skin require 3-5 times more UVR exposure to cause erythema. [15]

  • Hydration: UVR causes erythema in moist skin more effectively than dry skin. [19]

  • Environmental reflection: Radiation is 80% reflected by snow and ice, compared with 15% by sand. [14]

  • Ozone coverage: Increased levels of ozone filter out more UVR. [14]

  • Altitude: Thinner atmosphere at higher altitudes absorbs less UVR. [14]

  • Latitude: Exposure is greater nearer the equator. [14]

  • Time of day: UVR exposure is greatest from 10 am to 4 pm, when the sun is highest in the sky. [14]

  • Season: In locations outside the tropics, UVR is much greater in summer than winter. [14]

  • Cloud cover: Light clouds attenuate UVR by 10%, which may not be enough to protect from sunburn. [14]



Sunburns may exacerbate chronic diseases such as chronic actinic dermatitis, herpes simplex, eczema, and lupus erythematosus. [17]

Sunburns may be associated with other heat-related illnesses, including dehydration, heat exhaustion, and heatstroke.

Long-term exposure of the skin can lead to multiple deleterious effects, including premature aging and wrinkling of the skin (dermatoheliosis), development of premalignant lesions (solar keratoses), and development of malignant tumors (eg, basal cell carcinoma, squamous cell carcinoma, melanoma). [2]  A history of severe sunburn is associated with an increased risk of melanoma and other skin cancers, particularly in men. [22]   

Patients with sunburn may be at risk for UV keratitis. [23]