Given how maskol is used including quantity, frequency and duration, and how it is applied and its propensity toward direct skin contact, I am somewhat skeptical to that being the cause for your allergic reaction. Similar reactions can occur from eating certain foods, or exposures to other, non-hobby related items: plants, animals (including insect bites), and other chemicals, (including changes in soaps, deodorants, perfumes and after-shaves, etc.) The list is endless. The fact that maskol applied to your skin did not exacerbate or extend your symptoms should be somewhat of an indicator that maskol may have not been the culprit.
But, as Jeeves said, latex allergies do occur. If you wear latex gloves and suspect a latex allergy, switch to nitrile as a glove medium. Most, if not all, of the major hospitals around here have made that change. Nitrile gloves are just like latex in that they are thin, and give excellent tactile feedback just like latex. One of the real benefits of nitrile over latex, is that they don't degrade nearly as quickly in the presence of many organic solvents, so they are great for protecting your hands when handling paints, thinners, and the like.
Glad to hear you're on the mend!
Just my opinion,
Gip Winecoff