What Causes Pimple And Redness On Penis While On Azithromycin And Brufen?

Hello ,I recently had a terrible throat infection. There was some white pus deposits visible along the throat wall. I resorted to gargling with salted water at regular intervals and took some antibiotics, pain killers as the pain was unbearable. I had yo increase the dosage as it was not getting better.I ended up taking Azithromycin(400mg) for 5 days along with Brufin(400mg). On 3 of the days I doubled the doze to morning and evening.Question: The throat is better. Just around when yhe throat was getting better, towards the end of the course, the opening near the penis hood started getting red. Now, that red swollen area near the opening has got a slight pus (just like a pimple). I started drinking lots of water and the redness is mild but the pimple has not subsided and it pains when I urinate when the urine touches the pimple. Is this related to the overdose of the medicine? Can it related to eating mushrooms ?