The clue “Although most preventative medical ointments commonly in use” tells you that most ointments would prevent an infection, the one Helen used did not. Recycle the clue, and put a word that means prevent in the first blank; staved off is the best match. Work with the second and third blanks together. The ointment did not prevent an infection, and the clue “much to her dismay” tells you that something bad happened. The only pair that makes sense together is contributed to and affliction because they tell you that the ointment made her problem worse.