Pruritus sine materia:
- Pruritus sine materia is defined as pruritus with no visible elementary lesions or identified environmental factors.
- There is no evidence of contagiousness among the patient’s close contacts.
- There may be secondary scratching lesions (excoriation, lichenification, impetignization) may be present.
Grégoire tells you that he has a history of hypertension treated with an ARB. He has not noted any cases of pruritus among his close contacts. He tells you that the pruritus gets worse when showering and swimming.
Biological analyses show:
- haemoglobin 19.8 g/dL,
- haematocrit 61%,
- platelets at 495 g/L.
The rest of the assessment was unremarkable. As a reminder, Grégoire has pruritus that gets worse when he goes swimming.
This makes you think of aquagenic pruritus because the symptoms intensify after contact with water. Indeed, aquagenic pruritus corresponds to the onset of pruritus after contact with water, no matter its temperature. It may be associated with skin lesions or be sine materia. The symptoms should also make you suspect Vaquez’s polycythemia, sarcoidosis, Hodgkin lymphoma, haemochromatosis, and mastocytosis. Vaquez disease or polycythaemia is a myeloproliferative neoplasm.
You make a diagnosis of Vaquez disease and refer the patient to a haematologist colleague.
