PMF has been estimated to occur at 0.5 to 1.5 per 100,000 patients per year frequency.¹ The disease most commonly presents in the sixth and seventh decades of life. Both genders are equally affected. It rarely presents in children.² The most common sites for EMH are spleen and liver, but almost any organ can be involved. Skin involvement is an extremely rare manifestation, and only 16 cases have been reported.³

PMF is a member of the family of chronic myeloproliferative neoplasms that includes chronic myelogenous leukemia, essential thrombocythemia, polycythemia vera, chronic neutrophilic leukemia, chronic eosinophilic leukemia, and mastocytosis.⁴ EMH has also been reported in adults without known hematologic disorder.⁵

The original TORCH syndrome complex includes intrauterine infections by Toxoplasma gondii, rubella virus, cytomegalovirus, and herpes simplex virus types 1 and 2. Dermal erythropoiesis is mostly associated with Toxoplasma, cytomegalovirus, and rubella infections.⁶ The commonest hematologic etiologies causing reactive erythropoiesis include erythroblastosis fetalis, hereditary spherocytosis, and twin–twin transfusion syndrome.⁷

The clinical presentation of EMH is similar to those of other cutaneous metastases, such as the presence of pink or red-violaceous macules, papules, and nodules, typically on the trunk (Fig. 55-1). Bulla formation, hemorrhage, and ulcerations have also been observed.^5,8 Survival data have been reported in 16 cases with a median follow-up of 7 months (range, 1 to 60 months).^{7,9,10,11,12,13,14,15,16} Most patients died with a median survival of 2 months (range, 0 to 24 months). Only few patients survived at 36 and 60 months. As the median survival in PMF is 5 years, cutaneous involvement seems to portend a poor prognosis. No clear treatment guidelines exist for EMH. Rare reports on visceral and dermal EMH in PMF described the use of radiotherapy.¹⁷