Here I want to focus on the different kebab choices available at a typical kebab house according to allergen or intolerance. I don't mention every kebab variety, but rather focus on the traditional favorites outlined in the Common Kebabs entry. As I've indicated in previous posts, what's available may vary according to venue and region.
Gluten or wheat
If you suffer from a gluten or wheat allergy or intolerance, kebab restaurants are a bit tricky. It may not be hopeless, but you'll have to be extremely careful. In addition, as I've indicated, the larger and more touristic venues will be more likely to adapt to your demands.
Obstacle number one: in many kebab locals it is common to toast bread alongside meat on the grill. They may even place slices of bread right on top of whatever else is on the grill. As if that weren't enough, they also tend to pull the kebab off the skewer with bread to protect their hands. Therefore, it's vital that you ask about these practices right off the bat.
The difficulty doesn't end there. It is also common to place a few slices of bread underneath, as well as on top of a kebab when served. So even if you specifically order something because it's not served wrapped in bread, they just might smother it with a few pieces to make it extra delicious. Be sure to emphasize that no bread should touch anything on your plate. Furthermore, if you're considering an ocakbaşı you'll have to be very observant. There's generally one usta in charge of the entire grill, which means his hands are a great source of cross-contamination. You'll need to convince him to change his gloves and wash his cutting board and knife while tending to your order. While it's nice to be able to supervise your meal's preparation, I can't promise it won't be stressful. Like I said, kebab is a bit tricky. I almost forgot—be sure to cancel the side of bulgur or cracked wheat that will most likely accompany your order. It's the starch of preference in most kebab venues.
After all that, it's time to choose your kebab! Luckily, if you're only senstive to gluten or wheat, it's much easier from here on out. First of all, you'll have to steer clear of the Ali Nazik, Hünkar Beğendi, patlıcan and simit variations since they all contain wheat. The eggplant puree in Ali Nazik and Hünkar Beğendi contains flour, the meatballs in the patlıcan kebabı contain bread, and simit kebabı contains bulgur. Other than that, be careful when ordering beyti because it's almost exclusively served wrapped in bread. And if you choose saç kebabı, just be sure that it's not the phyllo dough or yufkalı version.
If you're interested in a minced variety, I recommend either Adana or Urfa, depending on whether you tolerate spiciness. Both are prepared on skewers rather than directly on the grill, which provides a degree of security. Though they resemble giant meatballs, generally they do not contain bread filling nor flour—but I'd ask just to be sure. Both çöp şiş and şiş kebabs are also very reasonable options. They are also cooked on skeweres, reducing the risk of contamination. With any of these options though, I would be sure to emphasize that they not touch your order with any bread. Finally, iskender or a portion of döner (as opposed to a sandwich or roll) are both suitable, as long as you insist that they not be accompanied by bread.
Dairy
Additionally, if you have a lactose intolerance and consume goat milk products, I would be reluctant to assume that any of the milk, yogurt or cheese products used in preparation are strictly produced from goats. I wouldn't trust everyone, but I'd encourage you to ask.
Corn
For those suffering from a corn intolerance or allergy, I would steer clear again of the Ali Nazik and Hünkar Beğendi kebab varieties, as corn starch may be used in the patlican puree. Though patlıcan and simit kebabs are generally prepared with wheat flour, I would avoid them as well. Corn starch may be included for flavoring. In addition, cheaper venues may prepare fried, stewed or even oven roasted meats in corn oil rather than butter or margarine to save on costs.
Eggs
Nuts & Seeds
When kebabing there are a few nuts and seeds you'll need to be cautious of: pistachios, walnuts, pine nuts and sesame seeds. Generally speaking the existence of nuts in kebab is explicit in the name of the kebab. For example, (Antep) fistık kebabı literally translates to pistachio kebab, and obviously contains pistachios. However, occasionally some restaurants may add them unexpectedly. Therefore, it's always a good idea to ask. Pistachios and pine nuts are the most commonly used, and most likely to surprise you in beyti or simit kebabs. If you were to come across any sesame seeds, they'd most likley be hiding in phyllo dough or yufka.