No one likes to be infected with any sort of pathogen, but some types are arguably worse than others. For instance, bacterial infections are often cleared up with a week’s worth of antibiotics. On the other hand, fungal infections can persist for months on end, with or without treatment. Some people suffer with toenail fungus or chronic recurrences of athlete’s foot for years! So why are fungal infections so much harder to eradicate? Andrew Y. Finlay, a professor of dermatology, explained the challenges of treating skin and toenail fungus in a review published in the British Medical Journal.