Fatal cytophagic panniculitis and haemophagocytic syndrome.

We present two fatal cases of cytophagic panniculitis (CP) and haemophagocytic syndrome (HPS). In the first of these, there was an underlying T-cell lymphoma but in the second no associated disease was found. HPS is a frequently fatal disorder of immune regulation, characterized by fever, histiocytic haemophagocytosis, hepatosplenomegaly, pancytopenia, hypertriglyceridaemia and coagulopathy; CP is a less common manifestation. A number of benign and malignant conditions may present with HPS, the clinical findings and investigations aiding in determining an underlying disorder. Therapy is both supportive and directed at any associated illness, but often very difficult as diagnosis is delayed.

Polymorphic light eruption: an immunopathological study of evolving lesions.

Polymorphic light eruption (PLE) papules were successfully induced on previously affected sites in 11 out of 14 patients with PLE 4-20 h after single exposures to suberythemogenic doses of solar simulated radiation. Histological examination of biopsies performed 1 h, 5 h, 24 h, 72 h and 144 h post-irradiation revealed onset within 5 h of perivascular cellular infiltration. The infiltrate was dominated by lymphocytes in both early and established lesions, without evident epidermal pathology. Immunohistochemistry demonstrated a predominance of CD4+ cells in lesions up to 72 h post-induction, but later biopsies were dominated by a CD8+ infiltrate. Significantly increased numbers of dermal macrophages and CD1b+ cells were detected 1 h and 5 h post-irradiation, respectively. These findings are consistent with a delayed type hypersensitivity response underlying the pathogenesis of polymorphic light eruption.