Substances such as thiols, thiocyanates, phenols and tannins can precipitate the pemphigus in a genetically predisposed individual. A list of foods containing these substances includes:
Vegetables: Garlic, onion, mustard, turnip, broccoli, radish, cabbage, cauliflower, potato, leek, shallots, chives, tomatoes, ginger
Fruits and nuts: Mango, raspberry, pistachio, avocado, cherry, cashew, banana, cranberry, guarana, pear, blackberry, walnut, peach
Masticatories and stimulants: Coffee, tea, betel nut leaf, Katha, cassava
Beverages: Beer, wine, soft drinks
Miscellaneous: Ice cream, candy, baked foods, spices (red chillies), aspartame, sodium benzoate, tartrazine, colouring agents, nutritional supplements
Water: High tannin content in Brazil river water may be the reason for endemicity of Fogo selvedge. Tannins can be removed by chlorination, which would explain why the incidence of Fogo selvedge has decreased with urbanization.