What are different causes of Type IV HS?

1. Bacterial causes are Mycobacterium tuberculosis, Brucellosis, Leprosy, and Syphilis. 2. Viral causes are Smallpox, Measles, Herpes simplex. 3. The fungal cause is Candidiasis, Histoplasmosis, and Coccidioidomycosis. 4. The protozoal cause is Leishmaniasis. 5. Chemical causes are hair dyes, nickel salt, chromium, potassium dichromate, silicosis, and berylliosis. 6. Drugs causes are penicillin and neomycin. 7. Crohn’s disease. 8. Schistosomiasis. 9. Sarcoidosis