title: [Urticarial vasculitis associated with essential thrombocythaemia progressing to myelofibrosis].
abstract: BACKGROUND
  Urticarial vasculitis (UV) is a rare form of leukocytoclastic vasculitis in which skin lesions resemble urticaria. UV comprises hypocomplementemic and normocomplementemic subtypes. To date, only 4 cases of UV associated with myeloproliferative disorders have been described, including 3 cases with essential thrombocythaemia (ET) and one case with polycythaemia vera.
  
  
  METHODS
  We describe the case of a 59-year-old male patient with JAK2-positive TE and secondary myelofibrosis and who developed multiple urticarial papules persisting for more than 24hours. Skin biopsy showed perivascular neutrophilic infiltrate with margination of neutrophils in the lumen of vessels and some leukocytoclastic patterns, and with red cell extravasation consistent with UV. Treatment with ruxolitinib (a JAK2 inhibitor) induced transient and partial control of the haematological symptoms but did not prevent UV flare. Prednisolone 20mg once daily was added, with good clinical response.
  
  
  CONCLUSIONS
  To our knowledge, this is the fourth reported case of UV associated with ET and the first case associated with MF.
authors.affiliation: Faculté de médecine, université de Parakou, BP 123 Parakou, Bénin; Service de dermatologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Koudoukpo
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Jachiet
authors.affiliation: Service d'hématologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: J-M
authors.initials: JM
authors.lastname: Zini
authors.affiliation: Service d'hématologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Andreoli
authors.affiliation: Service d'anatomo-pathologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Pinquier
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Rybojad
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: D
authors.initials: D
authors.lastname: Bosset
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: de Masson
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: M
authors.initials: M
authors.lastname: Bagot
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Lebbé
authors.affiliation: Service de dermatologie, hôpital Saint-Louis, 1, avenue Claude-Vellefaux, 75010 Paris, France. Electronic address: jean-david.bouaziz@sls.aphp.fr.
authors.forename: J-D
authors.initials: JD
authors.lastname: Bouaziz
mesh_terms: D001853:Bone Marrow / Q000473:pathology*; D004359:Drug Therapy, Combination; D017809:Fatal Outcome; D006801:Humans; D053614:Janus Kinase 2 / Q000037:antagonists & inhibitors; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D009196:Myeloproliferative Disorders / Q000150:complications* / Q000188:drug therapy; D009570:Nitriles; D011239:Prednisolone / Q000627:therapeutic use; D011720:Pyrazoles / Q000627:therapeutic use; D011743:Pyrimidines; D012867:Skin / Q000473:pathology; D013920:Thrombocythemia, Essential / Q000150:complications; D014581:Urticaria / Q000209:etiology*; D018366:Vasculitis, Leukocytoclastic, Cutaneous / Q000188:drug therapy / Q000209:etiology*
chemical_list: D009570:Nitriles; D011720:Pyrazoles; D011743:Pyrimidines; C540383:ruxolitinib; D011239:Prednisolone; C507924:JAK2 protein, human; D053614:Janus Kinase 2
keywords: Essential thrombocythaemia; Myelofibrosis; Myélofibrose; Ruxolitinib; Thrombocytémie essentielle; Urticarial vasculitis; Vascularite urticarienne