84 A new medical review highlights the complex relationship between haematological malignancies (HMs) and rare skin conditions, particularly neutrophilic and eosinophilic dermatoses. The study, conducted by a team of Italian researchers, underscores the challenges faced by dermatologists and haematologists in diagnosing and treating these conditions, which are often associated with blood cancers such as leukaemia and lymphoma. The findings were published in the journal Frontiers in Medicine. The report draws attention to the interplay between molecular abnormalities in blood disorders and their cutaneous manifestations. These skin conditions, which range from painful, inflamed patches to ulcerative lesions, can sometimes indicate the presence of underlying malignancies. The study reviewed a range of conditions, including Sweet’s syndrome, pyoderma gangrenosum, and eosinophilic dermatosis, each of which has been linked to various forms of blood cancers. Rapidly developing, painful, and inflamed lesions that appear alongside fevers and elevated white blood cell counts are the hallmark of neutrophilic dermatoses, such as Sweet’s syndrome. According to the study, up to 85% of malignancy-associated cases of Sweet’s syndrome occur in patients with haematological cancers, including acute myeloid leukaemia (AML), chronic lymphocytic leukaemia (CLL), and multiple myeloma. Sweet’s syndrome has been identified as both a reactive skin condition triggered by cancer treatment and as a direct manifestation of the cancer itself. Another significant skin condition highlighted in the review is pyoderma gangrenosum, a rare and severe ulcerative disease. People with pyoderma gangrenosum often have inflammatory diseases like Crohn’s disease. But it has also been linked to blood cancers, especially myelodysplastic syndromes (MDS) and IgA-type monoclonal gammopathy. Patients suffering from pyoderma gangrenosum endure rapidly enlarging ulcers, and the disease is difficult to treat, often requiring a combination of systemic steroids and targeted therapies. The researchers also examined eosinophilic dermatoses, which are marked by intense itching, plaques, and, in some cases, blistering. These conditions are strongly associated with chronic lymphocytic leukaemia (CLL) and other B-cell neoplasms. Eosinophilic dermatosis of haematological malignancy, a particular focus of the study, affects up to 8% of CLL patients. Its recurrent and relapsing nature poses a significant challenge for both diagnosis and management. The review also introduces the concept of myelodysplasia cutis, a relatively new entity observed in patients with myelodysplastic syndromes. This condition blurs the line between reactive and cancer-associated dermatoses, as it involves skin infiltration by non-blast myeloid cells linked to the underlying blood disorder. The Italian team emphasised the importance of early recognition and treatment of these skin conditions, noting that successful management of the underlying haematological cancer can often lead to improvement in the associated skin disease. But they caution that some of these conditions, such as Sweet’s syndrome and pyoderma gangrenosum, may be resistant to conventional treatments, particularly in cancer patients undergoing chemotherapy or other aggressive treatments. The findings highlight the need for further research to better understand the molecular mechanisms connecting haematological cancers with skin manifestations. While much remains to be learned, this study provides valuable insight into the complexities of managing patients with both haematological malignancies and associated skin conditions.