@Koda Koda, I don’t mean to pry, but I’m wondering about your husband’s dosage of allopurinol. I started with 100 milligrams, once daily. That eliminated my gout attacks, except when I really went crazy, like having 4 to 12 beers and then a massive steak. My doctor looked at my blood tests and increased it to 300 mg once daily, though I didn’t request a change.
Haven’t had any attacks on the higher dosage, and no side effects either. A ketogenic diet does change things, and if the body lessens the excretion of uric acid then gout attacks make sense. Whether it’s after a week, six weeks, or months as in your husband’s case, I feel for him - you said that even opioids didn’t help his pain, so that’s a serious deal.

A common shape for urate crystals in the body are spear-shaped things, and you talk about something that can cause pain in a joint!
On a diet ‘higher in carbohydrates,’ I’ve never seen that advocated before. I know that for some people, sugar definitely makes gout attacks worse, and there are often mentions of avoiding refined carbohydrates - sugar, white flour, pasta, etc.
There was a study of people fasting during Ramadan - blood levels of uric acid went up during the fast, but not significantly. https://www.ncbi.nlm.nih.gov/pubmed/25275760
If your husband is doing well now, then good. I was going to say that since it’s been months. might as well go with an increased dose of allopurinol, if the attack was still going on. Yes, might temporarily make an attack worse, but it might make it go away, too, whether immediately or after some very short-term increase.