Itch without skin lesion (pruritus sine materia)

Laboratory tests

• FBC
• CRP
• Serum creatinine with eGFR
• AST
• ALT
• GGT
• Alkaline phosphatase
• Bilirubin
• Fasting plasma glucose
• TSH
• Serum calcium
• Serum albumin
• Serum ferritin
• LDHif neededFirst step of the tests in the 2025 European S2k recommendation; also in the haematological, hepatic and drug-related pathways.
• Ureaif neededFirst step of the 2025 European S2k recommendation (creatinine and urea); the Revue du Praticien also lists it in older people.
• serum protein electrophoresisif neededPersistent pruritus despite non-contributory first-line tests (looking for gammopathy, with immunofixation).
• IgG levelif neededSuspected myeloma (immunoglobulin and light chain assays).
• HIV serologyif neededClinical suspicion or risky sexual intercourse; HBV and HCV also in case of liver involvement (cytolysis, cholestasis).
• HBVif neededClinical suspicion or risky sexual intercourse; HBV and HCV also in case of liver involvement (cytolysis, cholestasis).
• HCVif neededClinical suspicion or risky sexual intercourse; HBV and HCV also in case of liver involvement (cytolysis, cholestasis).
• Stool parasitology (if travel or eosinophilia)if neededSuspicion from the history (travel) and/or eosinophilia on FBC.
• IgA anti-tissue transglutaminase antibodies (tTG-IgA)if neededIron deficiency with no cause found: the British recommendation on generalised pruritus without skin disease (British Association of Dermatologists, 2018) then has tissue transglutaminase antibodies looked for, unless gluten has been excluded for at least 6 weeks ^[2]. In France, HAS (2026) also lists iron deficiency among the indications for coeliac disease testing, with IgA anti-tissue transglutaminase paired with total IgA ^[3]; the European recommendation on pruritus provides for this test only in case of signs of malabsorption ^[1].
• Total IgAif neededIron deficiency with no cause found: the British recommendation on generalised pruritus without skin disease (British Association of Dermatologists, 2018) then has tissue transglutaminase antibodies looked for, unless gluten has been excluded for at least 6 weeks ^[2]. In France, HAS (2026) also lists iron deficiency among the indications for coeliac disease testing, with IgA anti-tissue transglutaminase paired with total IgA ^[3]; the European recommendation on pruritus provides for this test only in case of signs of malabsorption ^[1].