infections
Chickenpox
Complications
Risk of complications from chickenpox is increased for newborns, adults, and people who have a weakened immune system or certain disorders. Lung infection ( Overview of Pneumonia ) resulting in cough and difficulty breathing may complicate severe chickenpox in adults, infants, and people of all ages who have a weak immune system. Pneumonia rarely develops in young children who have a normal immune system. Brain infection ( Encephalitis ) is less common and causes unsteadiness in walking, headache, dizziness, confusion, and seizures. In adults, encephalitis can be life threatening. Inflammation of the liver and bleeding problems may also occur. Reye Syndrome is a rare but very severe complication that occurs almost only in those younger than 18 following the use of People who get varicella while pregnant are at risk of serious complications, such as Overview of Pneumonia , and may die as a result. Chickenpox can also be transmitted to the fetus, especially if chickenpox develops during the first or early second trimester, or to the newborn during or after birth. Such an infection can result in scars on the skin, birth defects, low birth weight, or illness in the newborn. 