Differential Diagnosis for Right Big Toe and Left 2nd Toe Infection in a 33-Week Pregnant Woman

• Single Most Likely Diagnosis
  • Paronychia: This is an infection of the skin around the nail, which can be caused by bacterial or fungal pathogens. The symptoms of redness, purulence, and pain, especially after a pedicure, are consistent with paronychia. The use of OTC ointment may not have been sufficient to treat the infection, especially if it was bacterial in nature.
• Other Likely Diagnoses
  • Cellulitis: A bacterial infection of the skin and subcutaneous tissues, which can cause redness, swelling, and pain. The fact that the infection is localized to the toes and has developed after a pedicure suggests a possible entry point for bacteria.
  • Ingrown Toenail: This condition can cause pain, redness, and swelling, especially if the nail is pushing into the surrounding skin. The pedicure may have exacerbated an existing ingrown toenail.
  • Folliculitis: An infection of the hair follicles, which can be caused by bacterial or fungal pathogens. The symptoms of redness, purulence, and pain are consistent with folliculitis.
• Do Not Miss Diagnoses
  • Osteomyelitis: A bone infection that can be caused by bacterial or fungal pathogens. While less likely, osteomyelitis can be a serious complication of a toe infection, especially if left untreated. The patient's pregnancy status may increase the risk of complications.
  • Septic Arthritis: A joint infection that can be caused by bacterial or fungal pathogens. If the infection spreads to the joint, it can cause serious complications, including joint destruction and systemic infection.
  • Necrotizing Fasciitis: A rare but life-threatening infection of the skin and subcutaneous tissues, which can cause severe pain, swelling, and necrosis. While unlikely, this diagnosis should not be missed due to its high mortality rate.
• Rare Diagnoses
  • Erythrasma: A fungal infection that can cause redness, scaling, and itching in the interdigital spaces. While possible, this diagnosis is less likely given the acute onset and purulent nature of the symptoms.
  • Pitted Keratolysis: A bacterial infection that can cause small pits or craters on the surface of the skin, often accompanied by a foul odor. This diagnosis is less likely given the location and symptoms of the infection.