Acute Care Nurse Practitioner Exam Prep 2025 – Complete Practice Resource

The primary lesion of impetigo is best described as a thin-walled vesicle that easily breaks, leading to the characteristic honey-colored crust that is often seen in this condition. Impetigo is a superficial bacterial skin infection, commonly caused by Staphylococcus aureus or Streptococcus pyogenes. These vesicles typically appear on exposed areas of the skin, especially the face and limbs, and can become filled with serous fluid. Upon rupture, the vesicles release a fluid that dries and forms crusty scabs, giving the lesions their distinct appearance.

Other lesions mentioned in the options don't accurately represent the typical presentation of impetigo. For instance, discoloration with central necrosis pertains more to lesions found in other skin conditions, such as erosions. Raised nodules with pus might suggest a deeper infection or an abscess, which is different from the shallow nature of impetigo sores. Lastly, fissures around the mouth could occur in conditions like angular cheilitis but do not characterize the primary lesion of impetigo, which is primarily vesicular. Thus, the definition of the primary lesion of impetigo is accurately captured by the description of thin-walled vesicles that easily break.