How to Tell When a Rash Is Contagious

Rashes that are generally NOT contagious

Several common childhood rashes are caused by the body's own immune or inflammatory responses and cannot spread to others:

• Eczema (atopic dermatitis): A chronic inflammatory skin condition. Not contagious. Children with eczema can attend school and daycare without restriction related to the rash.
• Hives (urticaria): Raised, itchy welts triggered by an allergen, infection, or sometimes no identifiable cause. The hives themselves are not contagious, though an underlying infection (if any) might be.
• Heat rash (miliaria): Small red bumps from blocked sweat glands in hot conditions. Not contagious.
• Contact dermatitis: A localized rash from skin contact with an irritant or allergen (plants, soaps, metals). Not contagious to others.
• Roseola rash: By the time the pink rash appears after the fever resolves, the child is generally past the contagious stage.

Rashes that ARE commonly contagious

Rashes caused by infections — bacterial, viral, or fungal — can spread to other children or adults:

• Chickenpox: Highly contagious — up to 90% of unimmunized close contacts may become infected 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Chickenpox contagiousness — up to 90% of unimmunized close contacts infected; contagious from 1-2 days before rash to all lesions crusted; incubation period 10-21 days. A person is contagious beginning 1 to 2 days before the rash appears and until all blisters have crusted over 1Ref 1Centers for Disease Control and Prevention (2024).About Chickenpox (Varicella).Chickenpox contagiousness — up to 90% of unimmunized close contacts infected; contagious from 1-2 days before rash to all lesions crusted; incubation period 10-21 days.
• Impetigo: A bacterial skin infection producing honey-colored crusted sores, highly contagious through direct contact; children need antibiotic treatment before returning to group settings 2Ref 2American Academy of Pediatrics (2023).Impetigo: What to Know About This Common Skin Infection in Children.Impetigo as highly contagious bacterial skin infection; antibiotic treatment required before return to school; mild cases with covered lesions may not require exclusion.
• Hand, foot, and mouth disease: Contagious through direct contact with blisters, stool, and saliva.
• Ringworm (tinea): A fungal infection that spreads through skin contact or contaminated surfaces. Contagious until treatment has started and is improving.
• Scarlet fever: Contagious strep infection; children must be on antibiotics for at least 24 hours before returning to school 3Ref 3Centers for Disease Control and Prevention (2025).Clinical Guidance for Group A Streptococcal Pharyngitis.Scarlet fever return-to-school: must be afebrile and at least 12-24 hours into appropriate antibiotic therapy.
• Fifth disease (parvovirus B19): Contagious before the rash appears; generally not contagious once the distinctive cheek rash is visible.
• Molluscum contagiosum: A viral bumpy skin condition that spreads through direct skin contact, though most guidance does not recommend excluding children from school for this.

Fever plus rash: an important combination

A rash that appears with fever is more likely to reflect an active infection and warrants same-day contact with a pediatric provider rather than a wait-and-see approach. A fever with a rash does not automatically mean an emergency, but a provider can advise on whether an in-person visit is needed and whether the child should stay home.

How to assess a rash quickly

A few practical checks before contacting the provider:

The blanch test: Press firmly on the rash with a finger or a clear glass. If the redness fades (blanches) where you press and returns when you release, the rash is likely caused by surface blood vessel dilation — most common rashes do this. If the rash does NOT fade when pressed, this can indicate bleeding under the skin (petechiae or purpura) and should be evaluated urgently, as it can be a sign of a serious infection 4Ref 4Centers for Disease Control and Prevention (2024).About Impetigo.Impetigo caused by Group A Strep; highly contagious through direct contact; most common in children ages 2-5.

Location and pattern: A rash limited to one area of contact suggests dermatitis; a widespread rash is more often systemic (viral, bacterial, or immune). A rash that appears first on the cheeks then spreads to the limbs follows the pattern seen in fifth disease.

Other symptoms: A child who is ill-appearing, has a high or persistent fever, is unusually lethargic, has swollen lymph nodes, or has difficulty breathing alongside a rash needs prompt evaluation regardless of what the rash looks like.

School and daycare policies

School and daycare exclusion policies vary by setting and state. Most programs require confirmation of the diagnosis or a clearance note from a provider before a child with an obviously infectious rash can return. For impetigo, mild cases with fewer than two sores that are covered do not typically require exclusion; more severe cases generally require antibiotic treatment for more than 24 hours before return 2Ref 2American Academy of Pediatrics (2023).Impetigo: What to Know About This Common Skin Infection in Children.Impetigo as highly contagious bacterial skin infection; antibiotic treatment required before return to school; mild cases with covered lesions may not require exclusion. When uncertain, a quick call to the child's pediatric provider is often the fastest path to resolution.