We present the case of a woman in her 50s with past medical history significant for psoriasis treated with methotrexate on a stable dose for the past 20 years, diabetes mellitus and chronic kidney disease. In the setting of a long flight, dehydration and non steroidal anti-inflammatory drug consumption, the patient presented to the emergency department with oral mucositis and cutaneous erosions and ulcers of the psoriasis plaques. MTX levels were normal corroborated by three different measurements in 24 h. Initially the complete blood count tests were significant for macrocytic, thrombocytopenia (82.000 10³/L) and impaired kidney function. The patient was diagnosed of acute methotrexate toxicity and started on intravenous folinic acid. In 24 h the patient developed severe pancytopenia. She required treatment with colony-stimulating factors, platelet and blood transfusions. After 10 days, the CBC improved to normal levels and the cutaneous lesions resolved.