Erythromelalgia is a rare disease of unclear etiology, characterized by recurrent erythema, burning pain and warmth of the affected extremities. In erythromelalgia we can distinguish primary and secondary form. Secondary forms occur in the course of myeloproliferative disorders, systemic connective tissue disease, diabetes mellitus type 1 and 2, multiple sclerosis, neuropathies, infectious diseases, embolism, as well as trauma. Symptoms of EM result from pathological misdistribution of skin microvascular blood flow and dysfunction of adrenergic neurons. Primary EM develops due to mutation in SCN9A, the gene that encodes alpha subunit of the voltage-gated channel Nav 1.7. Erythromelalgia diagnosis based on clinical criteria. May the pain recurring character, usually occur symmetrically, often on the lower extremities than the upper, increases with increased ambient temperature during exercise, leaving the limbs down at night and after drinking alcohol. Only brings cool relief. Although described many trials of EM there is no conclusive data to support the efficacy of any of the drug. Due to the nagging aches and pains, and as a consequence of the significant impairment of the people affected by this disease erythromelalgia treatment focuses on the use of analgesics. In this paper authors reported 2 cases of primary familial erythromelalgia and difficulties with achieving a significant improvement with the currently available treatment, in an attempt to monitor the thermographic study treatment.