You have recently encountered 4 children with a very distinct, well-demarcated, flat erythroderma of the facial area. You must determine whether this rash is due to erysipelas, which presents with an erythematous flat, painful, cellulitis-like rash most commonly on the face or lower extremities. The differential diagnosis in each of these cases also includes allergic manifestations such as a drug hypersensitivity, angioedema, or contact dermatitis; local reactions such as sunburn or other thermal burn; viral infections, such as fifth disease, etc; and bacterial infections such as cellulitis, early staphylococcal or streptococcal scalded skin, and early necrotizing fasciitis. You will also likely be tested by some children who will fail your initial “prudent” antibiotic choice, as these cases will illustrate.
A previously healthy white, female 6-month-old presents to your office with fussiness, a 3-day-long fever of up to 103°F, decreased appetite, rhinorrhea, excessive drooling, and pulling at her ears. The mother has also noted occasional vomiting without diarrhea, poor sleeping, and tremendous clinginess. The child is fully immunized; she is receiving no medications except for ibuprofen every 8 hours.
In the office, her temperature is 101°F, pulse rate 134, respiratory rate 24, and oxygen saturation 99%. When you examine her she is fairly distractible and cooperative for her age. Her dermatologic examination reveals the rash seen in Figure 1. Her tympanic membranes are normal, and because she has now become much less cooperative after you removed the cerumen from her ear canals, a cursory look at her posterior pharynx shows it is fairly reddened. The remainder of her examination is normal, including the lymph nodes, lungs, heart, abdomen, vaginalrectal area, and range of motion of the extremities. Because she was so cranky and irritable, you obtain a complete blood count (CBC). While you are waiting on those results, something else bothers you about her examination.
Figure 1. A 6-month-old white female presents with 3 days of fever, crankiness, and a unilateral flat, non-tender, well-demarcated rash of the face only. Images courtesy of Stan L. Block, MD, FAAP.
A previously healthy white, female 8-month-old presents to your office on a September morning with abrupt 12-hour onset of irritability, fever to 102°F, no appetite, and no sleep the night before. She attends daycare, has had no gastrointestinal complaints, no tick bites, and has received no other medications except for an ibuprofen dose that morning. She is fully immunized and no other family members have been ill.
In the office her temperature is 101°F, pulse rate 144, respiratory rate 30, and oxygen saturation 97%. The nurse had an extremely difficult time obtaining her weight and her vital signs due to her crying. Her physical examination reveals the well-demarcated rash on the face (see Figure 2). She is very difficult to examine and you can find no way to distract her from crying. She looks ill but does not appear toxic. The remainder of her physical examination is normal, including the pharynx, tympanic membranes, supple neck, cervical nodes, heart, lungs, abdomen, and extremities. The rash localized solely on her face is surprisingly warm, blanches readily, and may even be tender and indurated. Despite her low-grade fever and being nontoxic, she is very irritable, and your clinical index of suspicion urges you to consider this child as having an entirely different level of illness. Something vague really bothers you about her clinical examination.
Figure 2. An 8-month-old white female presents with an abrupt-onset fever to 101.5°F, irritability, and a unilateral flat, well-demarcated, possibly indurated, red rash on the left side of her face.
In August, a previously healthy, fully immunized, white, male 15-month-old who recently has…