What Causes Red Itchy Blotches On The Skin After Taking Antibiotics?
Possible allergic reaction
Detailed Answer:
Hello XXXXXXX
Yes, this could be an allergic reaction to the antibiotic.
I recommend that you consider taking Benadryl (diphenhydramine) 50 mg every 6 hours, but also call the doctor who prescribed the metronidazole. They may want you to stop the metronidazole and give you an alternative antibiotic such as fidaxomicin.
As it is after hours, I advise that you call the number for your doctor and most likely you will get the answering service. Tell them the situation and they will connect you with the doctor on call for your own (unless he or she takes their own calls).
If the itching or hive type blotches get worse in spite of diphenhydramine, please go in to urgent care or ER to be seen where they may also add a short course of corticosteroids.
I hope this information helps. Please let me know if I can provide further information.