The following mnemonics are from Clinical Cases and Images:

Allergy and Immunology
See AllergyCases.org for the complete list.

Cardiology
CAD Risk Factors: HOPEFULS
DDx of Chest Pain: A 9 P SUM
A Systematic Approach to Reading an EKG: A RARE PQRST/DR IIEE

Pulmonology
DDx of Cough: BAD CAT TOM
DDx of Community acquired pneumonia (CAP): SLIM CV

GI
DDx of Lower GI Bleeding: H-DRAIN
DDx of Bowel Obstruction: HANG IV

Nephrology
DDx of Chronic Renal Failure: DUG HIPPO
DDx of Hyperkalemia: ART x 3
DDx of Hypokalemia: BAD LOAD
ARMADA - Acid-base balance work-up in 6 steps by answering 6 questions

Endocrinology
(to be added)

Hem/Onc
DDx of Thrombocytopenia: HIT SHOCK
DDx of Thrombocytosis: MAKE MAPS
Predisposing Factors for DVT: SICC PT
DDx of Bleeding Disorders: F-CAP
DDx of Leukocytosis with neutrophilia: SEPTIC BILLS

Rheumatology
DDx of Arthritis: HINTS

ID
Diagnosing Meningitis: Don’t MISS
DDx of Community acquired pneumonia (CAP): SLIM CV
DDx of Leukocytosis with neutrophilia: SEPTIC BILLS
DDx of Arthritis: HINTS

Neurology
Nervous System Physical Exam: CNS MD
DDx of Delirium: MAD HIVES
DDx of Coma: IT'S COMA
Diagnosing Meningitis: Don’t MISS