​Symptoms and Signs - Differential Diagnosis of Blastomycosis • Tuberculosis • Squamous cell carcinoma • Pyoderma gangrenosum • Mycobacterium marinum infection • Histoplasmosis • Giant keratoacanthoma • Bronchogenic carcinoma • Bromoderma • Bacterial pneu

Symptoms and Signs - Differential Diagnosis of Bladder Cancer • Urinary tract infection • Stone disease • Neurogenic bladder • Interstitial cystitis • Frequency-urgency syndrome • Endometriosis

Symptoms and Signs - ​Differential Diagnosis of Bites, Snake • Scorpion bite • Laceration or puncture wound • Insect bite • Harmless snakebite • Cellulitis

Symptoms and Signs - Differential Diagnosis of Bite Wounds • Bite from a rabid animal (often the attack is unprovoked) • Factitious injury

​Symptoms and Signs - Differential Diagnosis of Insect Bites and Stings • Stings: cellulitis, bites • Bites: stings, cellulitis

Symptoms and Signs - ​Differential Diagnosis of Back Pain • Vascular: leaking aortic aneurysm, subarachnoid or spinal hemorrhage/infarction • Trauma: injury to bone, joint, or ligament • Renal: hydronephrosis, calculus, neoplasm, renal infarction, pyelone

Symptoms and Signs - Differential Diagnosis of Back Pain in Children and Adolescents • Tumor • Trauma (muscle strain, vertebral fracture) • Syrinx • Spondylolysis, spondylolisthesis • Sickle cell crisis • Psychological problem • Inflammatory spondyloarthr

Symptoms and Signs - Differential Diagnosis of Back Pain, Viscerogenic Origin • Urolithiasis • Tubal pregnancy • Prostatitis • Peptic ulcer • Pancreatitis • Metastatic neoplasm (e.g., bladder, uterus, ovary, kidney) • Endometriosis • Diverticular spasm •

Symptoms and Signs - Differential Diagnosis of Baker’s Cyst • Varicosities • Tumors • Popliteal aneurysms • Lymphadenopathy • Ganglion • Deep venous thrombosis (DVT) • Abscess

Symptoms and Signs - Differential Diagnosis of Balanitis • Reiter’s syndrome • Psoriasis • Lichen planus • Leukoplakia • Erythroplasia of Queyrat • Carcinoma of the penis • Balanitis xerotica obliterans