This chapter describes disease processes in children for which dermatologic symptoms are diagnostic and serves as a reference for the presenting complaint of "rash" in children and young adults. Additional detailed descriptions of important skin diseases are provided in chapters in Section 20, "Dermatology," with chapter 248, "Initial Evaluation and Management of Skin Disorders" specifically outlining principles of evaluation of rashes in both children and adults. Several important disease entities presenting with rashes are covered extensively elsewhere within this text (e.g., Lyme disease, Rocky Mountain spotted fever). In addition to the discussion below, chapters in Section 20, "Dermatology," discuss diagnosis based on anatomic location of the rash.
Ask about fever and systemic symptoms, prior immunizations, potential human or animal contacts, recent bites or stings, travel, recent prescription or over-the-counter drug administration, and recent food and environmental exposure. Ask about the initial location of rash, the pattern and time frame of rash development, initial morphology, and whether any topical or systemic medications have been applied.
Most exanthems present as an isolated episode in a single child, but outbreaks can also develop in groups of children. When evaluating only a single child with a rash, the diagnosis can usually be made by routine history and physical examination. When several children develop similar-appearing skin lesions, obtain detailed contact and exposure history, and consider the need to involve specialty services or notify local public health authorities.
Perform a complete physical exam and obtain a full set of vital signs. Completely disrobe all patients and place in a gown; examine patients in a room with good lighting to avoid missing important findings. Most rashes are self-limited and benign in children, but some rashes may be the harbinger of serious illness. An ill-appearing child or a child with a nonblanching rash raises suspicion for a serious condition. Check the scalp, ears, neck, mucous membranes, all skinfolds, digits and web interspaces, palms, and soles. Look for ticks that may be adherent in hair-bearing areas or skinfolds. Identify the morphology and determine the location and distribution of the rash.
Enteroviruses are a very common cause of illness and rash in young children. Enteroviruses are small, single-stranded RNA viruses belonging to the picornavirus group and include polioviruses, coxsackievirus, and echovirus.1 The enterovirus family has been associated with a wide variety of illnesses, including polio. Enterovirus infections usually occur in epidemics, with a peak prevalence in the summer and early fall. Transmission usually occurs by the fecal–oral route and sometimes by respiratory or oral–oral transmission.2
The clinical signs and symptoms of infection with coxsackieviruses and echoviruses vary and can include nonspecific febrile illnesses, upper and lower respiratory infections, GI infections and inflammations, aseptic meningitis, or myocarditis. Similarly, the associated skin manifestations include an array ...