Lesions That Point to Serious Bacterial Infections

August 31, 2009

Purpuric pustules can present diagnostic challenges. However, the ability to correctly identify these lesions can be of crucial-even lifesaving-importance in caring for ill children.

Purpuric pustules can present diagnostic challenges. However, the ability to correctly identify these lesions can be of crucial-even lifesaving-importance in caring for ill children. The 2 dermal inflammatory processes pictured here are both associated with serious bacterial infections. The lesion on the bottom top (A) is typically seen with symptoms of fever and sore joints, while the lesions on the bottom (B) are usually seen in patients who have fever and flu-like symptoms.

Can you identify the 2 infectious processes?

(Answer on next page.)

(A) Disseminated gonococcal infection; (B) meningococcal infection

The early lesions in both gonococcemia and meningococcemia are often dermal infiltrated inflammatory papules with little pus or purpura. Mature lesions may develop varying degrees of purpura, pus, and ulceration.

The progression of the cutaneous lesions of disseminated gonococcemia is shown in Figures 1 and 2. The lesions are the result of septic emboli, and culture of a specimen from one will grow gonococci. As in the patients pictured here, the lesions of gonococcemia are usually acral, sparing the torso. Typically, only a few lesions are present. For more information on disseminated gonococcal infection, see “Sexually Transmitted Infections in Teens: Reading the Skin Signs,” by David S. Reitman, MD (CONSULTANT FOR PEDIATRICIANS, June 2009 special issue on dermatology, page S20).

The rash of meningococcemia, which usually begins as a petechial eruption, tends to become more ecchymotic and is characterized by large areas of ischemic necrosis. The rash typically develops on the trunk and lower extremities. Figures 3 and 4 show the meningococcal rash in its definitive stages. For more information on meningococcemia, see “Meningococcal Disease: Suspect It, Treat It, Prevent It,” by Sara J. Mola, MD, Linda S. Nield, MD, and Martin E. Weisse, MD (CONSULTANT FOR PEDIATRICIANS, April 2009, page 116).