This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacterial infections, Subject name: Dental
Ecthyma gangrenosum seen in? 
Select and explain. 
A. Pseudomonas septicemia, B. Lepromatous leprosy, C. Ulcerative colitis, D. All of the above
A: Pseudomonas septicemia
Answer: A: Pseudomonas septicemia 
Explanation: Ecthyma Deeper variant of impetigo Indurated lesion with necrotic crust=on removal=forms ulcer Three types Ecthyma gangrenosum - Pseudomonas aeruginosa Ecthyma pyogenicum - Strep, Staph aureus Ecthyma contagiosum / Contagious pustular disease / Orf disease - Parapox virus/ORF virus. It is zoonotic viral condition which spreads sheep goat. Pseudomonas septicaemia most commonly occurs in the severely compromised host.