What happens when you culture an intact bulla in a case of staphylococcal scalded skin syndrome?

In cases of staphylococcal scalded skin syndrome (SSSS), the condition is characterized by the production of exfoliative toxins by Staphylococcus aureus. These toxins lead to the separation of the skin layers and the formation of blisters or bullae. When you culture an intact bulla from a patient suffering from SSSS, it is important to note that the blisters themselves are formed as a result of the skin's reaction to the toxins and not from a direct infection.

The fluid contained in the bulla is typically sterile because the underlying process does not involve significant bacterial invasion at the site of the blister; instead, the disease is a result of the toxins released into circulation. As a result, the culture will yield no growth of bacteria, thus being sterile. This serves to differentiate staphylococcal scalded skin syndrome from other skin infections that involve bacterial colonization, where you would expect to find bacterial growth in cultures from lesions.

In summary, the sterile nature of the bulla culture reflects the underlying pathophysiology of SSSS, which is mediated by toxins rather than a bacterial infection at the blister site.