Porth's Essentials of Pathophysiology, 4e

1179

Disorders of Skin Integrity and Function

C h a p t e r 4 6

Skin Manifestations of Common Infectious Diseases

Infectious childhood diseases that produce rashes include roseola infantum, rubella, rubeola, and vari- cella. Because these diseases are seen less frequently than in the past because of successful immunization programs and the use of antibiotics, they may be misdiagnosed or their diagnosis may be delayed. Roseola Infantum. Roseola infantum (exanthem subi- tum or sixth disease) is a contagious disease caused by human herpes virus type 6 (HHV-6). 70 Because HHV-6 is the etiologic agent, the condition is often referred to as sixth disease . Primary HHV-6 infection occurs early in life. More than 95% of roseola cases occur in chil- dren younger than 3 years of age, with a peak at 6 to 15 months of age. 70 Transplacental antibodies likely protect most infants until 6 months of age. Roseola produces a characteristic maculopapular rash covering the trunk and spreading to the appendages. The rash is preceded by an abrupt onset of high fever ( ≤ 105°F), inflamed tympanic membranes, and coldlike symptoms usually lasting 3 to 4 days. These symptoms improve at approximately the same time the rash appears. Because infants with roseola exhibit a unique constellation of symptoms over a short time, the infection may be con- fused with other childhood illnesses. Blood antibody titers may be taken to determine the actual diagnosis. In most cases, there are no long-term effects from this disease. Infants who spike high temperatures should be seen by their health care providers. Rubella. Rubella (i.e., 3-day measles or German mea- sles) is a childhood disease caused by the rubella virus. It is characterized by a diffuse, punctate, macular rash that begins on the trunk and spreads to the arms and legs (Fig. 46-26). Mild febrile states occur (usually <100°F). Postauricular, suboccipital, and cervical lymph node adenopathy is common. Coldlike symptoms usually accompany the disease in the form of cough, congestion, and coryza (i.e., nasal discharge). Rubella usually has no long-lasting sequelae; how- ever, the transmission of the disease to pregnant women early in their gestation periods may result in congeni- tal rubella syndrome. Among the clinical signs of con- genital rubella syndrome are cataracts, microcephaly, mental retardation, deafness, patent ductus arteriosus, glaucoma, purpura, and bone defects. Most states have laws requiring immunization to prevent transmission of rubella. Immunization is accomplished by live-virus injec- tion. Rubella vaccination has close to a 100% immunity response in treated children. Many states require a sec- ond preschool or later dose of rubella vaccine to increase immunity. Cases and outbreaks of rubella occur in the United States, especially among foreign-born unvacci- nated adults. Rubeola. Rubeola (measles, 7-day measles) is an acute, highly communicable viral disease caused by a morbil- livirus. 71 The characteristic rash is macular and blotchy;

sometimes the macules become confluent (Fig. 46-27). The rubeola rash usually begins on the face and spreads to the appendages. There are several accompanying symptoms: a fever of 100°F or greater, Koplik spots (i.e., small, irregular red spots with a bluish-white speck FIGURE 46-26. Rash of rubella on a child’s back. Distribution is similar to measles (rubeola), but not as intense. (From the Centers for Disease Control and Prevention Public Health Image Library. No. 712.)

FIGURE 46-27. Child with measles (rubeola) showing the characteristic conjunctivitis, coryza, and red, blotchy rash that appear around day 3 of illness, first on the face and then becoming more generalized. (From the Centers for Disease Control and Prevention Public Health Image Library. No. 1150.)