Dermatologic causes of pruritus
Dry skin (Xerosis)
Atopic dermatitis (eczema)
Allergic/irritant contact dermatitis
Urticaria (hives)
Dermatophyte (tinea) infections – e.g. Pedis, Corposis, Cruris, Capitis.
Scabies
Pediculosis (lice infestation)
Insect Bites
Folliculitis
Lichen simplex chronicus
Lichen planus
Psoriasis
Fungal infections
Sunburn
Polymorphous light eruption
Pityriasis rosea
Electrostatic charges (nylon and wool friction)
Plaster of Paris casts
Fiberglass and other irritants
Photodermatitis
Bullous pemphigoid

Systemic causes of Pruritus
Pregnancy, third trimester
Hepatobiliary causes:
Cholestasis
Primary biliary cirrhosis
Cholestasis of pregnancy
Oral contraceptives
Extrahepatic biliary obstruction; Chronic pancreatitis with obstruction of biliary tracts
Hepatitis C
Hepatitis (other than C)
Drug-induced cholestasis
Sclerosing cholangitis
Hematologic /Hematopoietic:
Myeloproliferative disorders
-Polycythemia vera
-Hodgkin’s disease
-Multiple myeloma
-Cutaneous T-cell lymphoma (mycosis fungoides)
Mastocytosis
Iron deficiency anemia
Hemochromatosis
Plasma cell dyscrasias
Endocrine and Metabolic:
Thyroid disease (Hyperthyroidism; Hypothyroidism)
Hyperparathyroidism
Chronic renal disease (uremia)
Diabetes mellitus
Neoplastic:
Leukemia; Lymphoma
Multiple myeloma
Carcinoma (solid tumors with paraneoplastic syndrome): Breast, lung, gastric
Carcinoid syndrome (due to a carcinoid tumor)
Autoimmune:
Sjögren syndrome
Dermatitis herpetiformis
Dermatomyositis
Linear immunoglobulin A disease
Infectious disease
HIV / AIDS
Infectious hepatitis
Parasitic disease (giardiasis, onchocerciasis, schistosomiasis, ascariasis)
Prion disease
Neuropsychiatric
Cerebral abscess
Cerebral tumor
Multiple sclerosis
Stroke
Eating disorders with rapid weight loss
Neuropathic pruritus (diabetic neuropathy, genital neural impingement)
Psychiatric (delusional parasitosis)
Drugs & drug withdrawal
Narcotics, calcium channel blocker, hydrochlorothiazide, angiotensin-converting enzyme inhibitors, salicylates, chloroquine, allergic reaction, cholestasis, amphetamines, cocaine
Foods (bananas, coffee)|
Transient acantholytic dermatosis (Grover’s disease)
Miscellaneous
Asthma
Atypical angina

Thinking about the differential diagnosis
It helps to divide the causes of pruritus into two major groups: dermatologic causes and systemic causes.

Further Reading
J Clin Aesthet Dermatol. 2009 Jul; 2(7): 30–36. Pruritus. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2924137/
Ann Dermatol. 2011 Feb; 23(1): 1–11. Chronic Pruritus: Clinics and Treatment. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3119985/
P T. 2012 Apr; 37(4): 227-232, 236-239. Pruritus in the Elderly. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351862/
Biomed Res Int. 2014; 2014: 541867. Pruritus in Female Patients. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3966341/
J Dtsch Dermatol Ges. 2013 Jan;11(1):31-42. “The itching hand”- important differential diagnoses and treatment.” https://www.ncbi.nlm.nih.gov/pubmed/23176572
Hippokratia. 2007 Apr-Jun; 11(2): 67–71. Pruritus in certain internal diseases. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2464269/
Am Fam Physician. 2011 Jul 15;84(2):195-202. A Diagnostic Approach to Pruritus. https://www.aafp.org/afp/2011/0715/p195.html

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