Perianal itching is not an uncommon problem; it is usually caused by irritation of the perianal skin.
This could be due to skin problem like dermatitis, anorectal diseases like piles and fissures or local irritation by excess sweat secretions, excess cleaning or irritant creams.
Dermatitis in this area could be due to infections with fungal, bacterial or parasitic organisms.
Being a moist area, infections with fungi and other organisms can occur resulting in inflammation and irritation in this area, Excess rubbing and scratching of the inflamed skin and may explain why you find blood when you clean yourself.
This area is also exposed to organisms that are normal inhabitant in the large bowel or excreted in stools. When the skin is damaged by rubbing or scratching or is moist by excess sweat it becomes a good medium for these organisms to grow, so more intense itching is felt and so on.
It is also possible that this could be due to piles, it is the commonest cause of fresh blood per rectum and if inflammation occurs around you may feel more perianal itching, bleeding and pain.
I would advise you to follow up with your doctor, direct clinical examination is essential to exclude serious causes like malignancy although unlikely based on your description.
Please keep us updated.
This answer does not substitute for direct medical consultation.
Dr. Safaa Mahmoud.
MB BCh, MSc Internal Medicine. MD Medical Oncology.
PhD Experimental Medicine and Biochemical Science.