Thanks for posting your query.
Presence of itching along with tickling sensation around anus suggests the diagnosis of pin worm (Enterobius
Pin worm lead down its egg around anal skin and its get attached under nails during itching around anal skin.
When the same infected hands is used for making food and eating meals, eggs again gets entry inside the gastrointestinal tract. Thus once infected, if left untreated or partially treated, may cause persistent infection.
You should consult with internal medicine specialist and microbiologist and should go for stool examination.
If stool examination is found to be negative for parasites then localized eczematous dermatitis
may be possible.
You should apply vaseline along with moisturizing cream for preventing dry.
Dr. Mayank Bhargava