Question
I have a lime tree that produces good lime juice. The fruit has bumps, almost like pimples, that have brown spots on the top of the "pimple" What causes this and what, if anything, can I do about it?

Answer
Hi Gary, Sounds like scab which will not effect your fruit, just not look pretty.

Citrus Scab (Elsinoe fawcetti)
Like greasy spot and melanose, this disease is most prevalent during the rainy season. Young leaves, stems, and fruit are most susceptible to infection. The major symptom is development of corky outgrowths in infected tissues (Browning et al., 1995). Citrus scab is usually not a major disease on limes and is usually controlled by the same foliar treatments for greasy spot and melanose.

You could use a copper spray which is used for fungal problems.  I would check into Atomic Grow which is organic and will not cause later problems like copper.  kathy