​Differential diagnosis of Pericardial Effusion 
-congestive heart failure 
-hemopericardium 
-pericarditis 
-constritive pericarditis 
-restrictive cardiomyopathy 
-cardiac tamponade 

​Differential diagnosis of causes of Perianal Fistula 
-rectal tuberculosis 
-cancer 
-lymphogranuloma venereum 
-Crohn’s disease

​Differential diagnosis of etiology of Peptic Ulcer Disease
-idiopathic 
-acid hypersecretion such as Zollinger – Ellison Syndrome / gastrinoma 
-NSAIDS

​Differential diagnosis of peptic ulcer disease
-esophageal rupture 
-gastric volvulus 
-ruptured aortic aneurysm 
-angina pectoris 
-gastric cancer
-pancreatic cancer 
-indigestion from overeating, high fat foods, coffee
-gastroesophageal reflux disease
-reflux esophagitis 
-biliary disease 
-pancreatitis 
-gastritis such as NSAIDS, stress, alcohol, H.pylori, pernicious anemia 
-functional dyspepsia 

​Differential diagnosis of Penile Ulcer
-lichen planus 
-glans neoplasm 
-systemic lupus erythematosus 
-Behcet’s Syndrome (glans)
-trauma 
-granuloma inguinale 
-lymphogranuloma venereum 
-chancroid 
-primary syphilis ( chancre)
-herpes simplex

​Differential diagnosis of Penile Papules 
-vitiligo 
-bowenoid papulosis 
-neoplasm 
-psoriasis 
-lichen plants 
-herpes simplex 
-lice 
-scabies 
-syphilis 
-molluscum contagiosum 
-genital warts ( condyloma)
-pearly penile papules 

​Differential diagnosis of Penile Pain 
-trauma 
-passage of urinary calculus 
-prostatitis 
-priapism 
-Peyronie’s Disease
-paraphimosis in uncircumcised 
-Balanitis such as candidiasis 
-herpes simplex 
-urethritis 

​Differential diagnosis of pemphigus vulgaris 
-graft versus host disease
-herpes gestationis 
-staphylococcal scalded skin syndrome 
-epidermolysis bullosa 
-porphyria cutanea tarda 
-pemphigus foliaceus 
-linear IgA dermatosis 
-paraneoplastic pemphigus 
-cicatricial pemphigoid 
-dermatitis herpetiformis 
-contact dermatitis 
-bullous impetigo 
-erythema multiforme major 
-toxic epidermal necrolysis 
-drug eruption 
-bullous pemphigoid