Hello and welcome to HCM,
Cystic acne and digestive problems are two separate issues and have to be dealt separately.
Deficiency of vitamin B 12 is associated with
aphthous ulcers in
oral mucosa but no such problem is associated with cystic acne.
The sores that you mentioned on roof of palate may be aphthous ulcers.
I suggest you to take vitamin B 12 supplements regularly.
When acne is infected, it leads to cystic acne.
Acne is caused due to plugging of pores and further infection of acne leads to formation of cysts, boils which may break out.
This is called cystic acne.
Underlying etiology of acne is
hormonal imbalance and / or oily skin.
Local treatment of acne consists of application of antibiotic ointment.
Vitamin A preparation is also helpful to unclog the pores helping to prevent further formation of acne.
In case there is hormonal imbalance especially in females, appropriate hormonal treatment is required.
Other measures that you can take are avoid touching the acne, avoid taking foods with high
glycemic index or high quantity of sugars.
Regarding your digestive issues, skipping of meals is an unhealthy practice.
It may act paradoxically and may lead to weight gain.
Balanced multiple small meals, plenty of water, fiber, regular exercise are key to good health and maintenance of appropriate weight.
Please
consult a dermatologist for treatment of your cystic acne.
Thanks and take care
Dr Shailja Puri