Herpes labialis (oral Herpes simplex)

Cold sore; Fever blister; Herpes simplex - oral

Warning symptoms of itching, burning, increased sensitivity, or tingling sensation may occur about 2 days before lesions appear.

• Skin lesions or rash around the lips, mouth, and gums
• Small blisters (vesicles) filled with clear yellowish fluid
  • Blisters on a raised, red, painful skin area
  • Blisters that form, break, and ooze
  • Yellow crusts that slough to reveal pink, healing skin
  • Several smaller blisters that merge to form a larger blister
• Mild fever (may occur)

Diagnosis is made on the basis of the appearance or culture of the lesion. Examination may also show enlargement of lymph nodes in the neck or groin.

Viral culture or Tzanck test of the skin lesion may reveal the herpes simplex virus.