Pruritus - Generalized Differential Diagnosis Algorithm - Systemic and Primary Causes == Primary Skin Lesions == Macules / Papules / Plaques: • Xerosis (dry skin) • Atopic dermatitis • Nummular dermatitis • Seborrheic dermatitis • Stasis dermatitis • Psoriasis • Lichen Planus • Infestations (scabies, lice) • Arthropod bites Vesicles/Bullae: • Varicella zoster (chickenpox) • Dermatitis herpetiformis • Bullous pemphigoid Wheals/Hives: • Urticaria == No Primary Skin Lesion / Systemic == Blood Glucose: • Diabetes Mellitus Liver Function Tests/Enzymes: • Cholestatic liver disease Creatinine & BUN: • Chronic renal failure/uremia TSH & T4: • Hypothyroidism • Hyperthyroidism CBC & Differential: • Lymphoma • Leukemia • Polycythemia rubra vera • Essential Throbocythemia • Myelodisplastic syndrome Psychiatric Disease: • Delusions of parasitosis #Pruritus #primary #secondary #systemic #generalized #dermatology #Differential #Diagnosis #Algorithm #causes
