Erythema multiforme produces distinctive “target lesions” that look like a bullseye or dartboard on the skin. Each spot has three concentric rings: a dark or dusky center, a pale middle ring of swollen skin, and a red outer rim. These targets typically appear on the hands, arms, feet, and legs, and the rash is usually symmetrical on both sides of the body.
The Classic Target Lesion
The hallmark of erythema multiforme is a round, flat or slightly raised spot with a layered appearance. At the center, the skin looks dark, sometimes appearing red, purple, or even bluish-black. This dusky core may blister or crust over. Surrounding that center is a ring of pale, slightly puffy skin caused by localized swelling. The outermost ring is a bright red band that gives the lesion its bullseye shape.
Not every lesion looks this textbook-perfect. Some spots appear as simple raised red bumps or flat patches without clearly defined rings. Others may look like hives. A single outbreak can include a mix of these forms, which is where the name “multiforme” (meaning many shapes) comes from. The classic three-ring target is the most recognizable, but it’s not the only presentation.
Individual lesions are typically small, ranging from a few millimeters to a couple of centimeters across. They tend to appear in clusters rather than as isolated spots.
Where the Rash Appears
Erythema multiforme has a strong preference for the extremities. The backs of the hands, palms, tops of the feet, and soles are the most common starting points. From there, the rash often spreads up the arms and legs, sometimes reaching the elbows and knees. The face and trunk can be involved but are less typical, especially in milder cases.
The rash is almost always symmetrical. If target lesions appear on your right hand, you’ll likely see matching spots on your left hand. This mirror-image pattern is one of the features that helps distinguish erythema multiforme from other skin conditions that look similar at first glance.
Minor vs. Major Forms
Erythema multiforme minor is the more common version. The rash stays mostly on the skin, with little or no involvement of the lips, mouth, or other moist tissue. In contrast, erythema multiforme major affects two or more mucous membranes, including the mouth, eyes, or genitals, along with more variable skin involvement.
When the mouth is affected, you may see painful red patches, swelling, or shallow sores on the lips, inner cheeks, tongue, or gums. The lips can become cracked and crusted, sometimes making it difficult to eat or drink. Eye involvement can cause redness, tearing, and a gritty sensation. Genital sores look similar to oral lesions: red, raw patches that are tender to the touch.
How It Feels
The rash is both painful and itchy in most cases. The skin around the lesions often feels swollen and tender, and touching the spots can be uncomfortable. Some people describe a burning sensation, particularly when lesions develop on the palms or soles. Itching can range from mild to intense enough to interfere with sleep.
Mucosal sores tend to be more painful than the skin lesions. Mouth involvement in particular can make eating, drinking, and talking uncomfortable. Fatigue, mild fever, and a general feeling of being unwell sometimes accompany the rash, especially in the major form.
Timeline of an Outbreak
A typical outbreak lasts two to four weeks from start to finish. New lesions may continue to appear over the first week or so, which means you might see spots at different stages of development at the same time. Some will look fresh and red while others are already fading. Older lesions gradually flatten, lose their ring pattern, and darken before resolving.
Once the rash clears, it usually heals without permanent scarring. Skin lesions commonly leave behind temporary discoloration, either darker or lighter patches, that can linger for weeks to months before the skin tone evens out. Mucosal lesions in the mouth or eyes generally heal completely without lasting marks, though in rare cases skin lesions can leave minor scars.
What Triggers the Rash
Herpes simplex virus is the most common trigger, responsible for up to 70% of recurrent cases. The erythema multiforme outbreak typically appears one to three weeks after a cold sore or genital herpes flare. In many cases, the herpes sore has already healed by the time the target lesions show up, so the connection isn’t always obvious. Viral DNA from herpes has been detected in the skin lesions of roughly half to 60% of people with recurrent outbreaks.
Infections caused by other organisms, particularly the bacterium that causes walking pneumonia, are another well-known trigger. Medications, including certain antibiotics and anti-seizure drugs, can also set off an episode, though drug-triggered cases are less common than infection-triggered ones.
How It Differs From More Serious Conditions
Erythema multiforme is sometimes confused with Stevens-Johnson syndrome (SJS), a rarer and more dangerous skin reaction. The key differences are location and severity. Erythema multiforme targets the extremities and produces true three-ring bullseye lesions. SJS tends to concentrate on the trunk and face, produces flatter, irregularly shaped spots, and causes more widespread blistering and skin peeling. When skin detachment covers more than 10% of the body surface, the condition is classified as SJS or its more severe form, toxic epidermal necrolysis.
Erythema multiforme is largely self-limited. Most people recover fully within a few weeks, though repeat episodes are common, particularly in those with recurrent herpes infections. Some people experience several flares per year, each following the same pattern of target lesions on the hands and feet that resolve on their own.