Causes of anal itch
Infections- Parasites (Pinworm, scabies)
Bacterial infections (Group A, Beta-hemolytic Streptococus, staphylococcus aureus),Fungal infections (particularly candida)
Sexually transmitted diseases (condyloma, herpes, syphilis, gonorrhea)
Fecal Soiling
Encopresis,Incontinence (usually post anorectal and bowel surgeries)
Chronic diarrhea,Poor hygiene
Transient internal relaxation of the internal anal sphincter
Anatomic abnormalities (eg. prolapsed internal hemorrhoids, rectal prolapse)
Local irritation
Excessive use of soap and detergents
Use of local creams and medications
Dietary agents
Coffee,Cola,Beer,Tomatoes,Chocolate,Tea,Citrus fruits
milk
Anorectal diseases
Abscesses,Fissures,Fistulas
Dermatologic diseases
Psoriasis,Contact dermatitis,Atopic dermatitis
Hidradenitis suppurativa,Paget's disease
Systemic diseases
Diabetes mellitus,Hepatic diseases (hyperbilirubinemia)
Leukemia,Thyroid disorders
Post operative conditions
Psychological causes
Other
Chemotherapy