Paula,
The treatment for dermatitis herpetiformis is completely different than the treatment for mastocytosis. DH is a symptom of gluten sensitivity, whereas mastocytosis is caused by excess numbers of mast cells and overactive mast cells. So yes, IMO mastocytosis should be treated with plenty of vitamin D and antihistamines. It's also possible that a GF diet might help, because gluten sensitivity is a common cause of skin issues. But remember that I am not a doctor, so this is just my opinion, it's not medical advice.
I'm not sure whether the Microscopic Colitis book would be helpful for your friend, but here's what I say about mastocytosis and vitamin D on pages 52–54 of the vitamin D book:
Is it any wonder that so many people, including physicians, are confused about how the immune system actually works?
It's a very complex and sophisticated system. And it can do wonderful things for us, provided that we just do our part to help keep it functioning properly. What this interdependent relationship implies then, is that vitamin D receptors must be present in adequate quantities in order for the active form of vitamin D to be able to prevent the production of excess numbers of mast cells when an inflammatory event is in progress. This is a mechanism that the immune system utilizes to prevent reactions from getting out of hand. Baroni et al. (2007) also demonstrated that VDR-deficient mice experience faster mast cell maturity rates than normal mice, and the mast cells that are produced are more easily-activated, compared with those produced by normal mice.
This phenomenon appears to explain why so many IBD patients tend to have mast cell activation disorder.
Mast cell activation disorder (MCAD) is a condition marked by inappropriate mast cell activation that results in the excessive release of histamine, cytokines, and other proinflammatory mediators by mast cells, for no legitimate (or at least no apparent) reason. It can cause many of the symptoms of mastocytosis or mastocytic enterocolitis, even though mast cell populations might be normal, or only slightly elevated.
The intestines are known to have relatively high populations of mast cells. MCAD can result in additional symptoms (due to IgE-based reactions) that cause complications, and add confounding issues to certain types of autoimmune diseases, such as IBDs.
In the case of microscopic colitis (of which lymphocytic colitis and collagenous colitis are the most common types) for example, MCAD appears to be capable of causing virtually any of the clinical gastroenterological symptoms traditionally associated with the disease, plus the addition of classic IgE-based allergy symptoms such as nasal discharge, watery eyes, and itching skin or tongue. These symptoms are usually somewhat attenuated (compared with classic allergic reactions), and they may even be overlooked, unless the patient is aware of this possibility, and remains alert, in order to notice the symptoms. But whether these symptoms are relatively minor, or severe, the additional mast cell activity typically results in increased severity of gastrointestinal symptoms normally associated with an IBD, and in some situations, this type of mast cell activity can even trigger a flare when an IBD has been in remission.
Presumably, this may also apply to the other IBDs, including Crohn's, ulcerative colitis, and celiac disease, although this possibility certainly hasn't yet been verified by random, double-blind research trials. Not all IBD patients experience these IgE-based symptoms, but for those who do, this observation should answer a lot of questions.
So a deficiency of either vitamin D receptors, or vitamin D in it's active form can lead to a hypersensitive condition where not only are mast cells more likely to degranulate (releasing proinflammatory agents), but additional mast cells are produced more rapidly, and more of them are ultimately produced, so that a state of severe hypersensitivity (resulting in massive inflammation) may be the result.
This condition appears to meet the definition of at least mast cell activation disorder, and it might possibly be the primary cause of mastocytic enterocolitis. It also may be associated with mastocytosis, which is a serious systemic form of mast cell disorder.
Here's the reference mentioned in that quote (Baroni et al. [2007]), since your friend might be interested in reading that reference:
12. Baroni, E., Biffi, M., Benigni, F., Monno, A., Carlucci, D., Carmeliet†, G., . . . D’Ambrosio, D. (2007). VDR-dependent regulation of mast cell maturation mediated by 1,25-dihydroxyvitamin D3. Journal of Leukocyte Biology, 81(1), 250–262. Retrieved from
http://www.jleukbio.org/content/81/1/250.full
Mastocytosis is very difficult to treat effectively. The leading experts on the treatment of this condition are located at Brigham and Women's Hospital in Boston (or they were trained there). The only doctors we have any information on who are qualified are listed here:
http://www.perskyfarms.com/phpBB2/viewtopic.php?t=14421
But if your friend doesn't have digestive system issues, then there would be no point in seeing a gastroenterologist. An immunologist trained at Brigham and Women's Hospital (under the direction of Dr. Mariana Castells) would be the best choice. Of course, it's also possible that your friend might be able to self-treat by using vitamin D and antihistamines (along with a GF diet for at least a few months, to see if it helps).
One thing to keep in mind though is the likelihood that even the experts at Brigham and Women's Hospital in Boston will not be aware of the role of vitamin D in mast cell suppression, because I doubt that they have read my book (or stumbled across the research that I based my observations on).
Tex