- **Allergies**: Reactions to foods, medications, plants, or other substances.
- **Infections**: Bacterial, viral, or fungal infections can cause rashes, such as those seen in chickenpox or ringworm.
- **Autoimmune conditions**: Diseases like lupus or psoriasis can cause chronic rashes.
- **Heat and sweat**: Heat rash can occur when sweat ducts become blocked and swell.
- **Irritants**: Contact with chemicals, soaps, or detergents can lead to contact dermatitis.
The treatment for a rash depends on its cause and severity. Common treatments include topical ointments, antihistamines, and avoiding known irritants. If a rash is severe, persistent, or accompanied by other symptoms like fever or difficulty breathing, medical attention should be sought