Methotrexate-induced papular eruption

Methotrexate-induced papular eruption
Synonyms
Pronounce	N/A
Specialty	N/A
Symptoms	Papules, rash, pruritus
Complications
Onset
Duration
Types	N/A
Causes	Methotrexate
Risks
Diagnosis	Clinical evaluation, skin biopsy
Differential diagnosis	Drug eruption, psoriasis, eczema
Prevention
Treatment	Discontinuation of methotrexate, topical corticosteroids
Medication
Prognosis
Frequency	Rare
Deaths

Methotrexate-induced papular eruption

Methotrexate-induced papular eruption is a dermatological condition characterized by the appearance of papules on the skin as a result of methotrexate therapy. Methotrexate is a disease-modifying antirheumatic drug (DMARD) commonly used in the treatment of various autoimmune diseases and certain types of cancer.

Pathophysiology

Methotrexate works by inhibiting the enzyme dihydrofolate reductase, which is crucial for the synthesis of nucleotides and, consequently, DNA replication and cell division. This mechanism is beneficial in slowing down the rapid proliferation of cells in conditions like psoriasis and certain cancers. However, it can also affect normal skin cells, leading to adverse dermatological reactions such as papular eruptions.

Clinical Presentation

Patients with methotrexate-induced papular eruption typically present with small, raised, red or skin-colored papules. These lesions are often distributed symmetrically and can appear on the trunk, extremities, and occasionally on the face. The papules may be accompanied by pruritus (itching) and can vary in number and size.

Diagnosis

The diagnosis of methotrexate-induced papular eruption is primarily clinical, based on the patient's history of methotrexate use and the characteristic appearance of the skin lesions. A skin biopsy may be performed to rule out other conditions and to confirm the diagnosis. Histopathological examination typically shows features of a drug-induced eruption, such as lymphocytic infiltrate and epidermal changes.

Management

Management of methotrexate-induced papular eruption involves discontinuation or adjustment of methotrexate therapy. In some cases, reducing the dose or switching to an alternative medication may be necessary. Topical treatments, such as corticosteroids, can be used to alleviate symptoms. In severe cases, systemic treatments may be required.

Prognosis

The prognosis for methotrexate-induced papular eruption is generally good, especially if the offending drug is discontinued or the dose is adjusted. The skin lesions typically resolve without scarring once methotrexate is withdrawn or the dose is reduced.

Prevention

Preventive measures include careful monitoring of patients on methotrexate therapy, especially those with a history of drug-induced skin reactions. Regular follow-up and patient education about potential side effects can help in early detection and management of adverse reactions.

Related pages

• Methotrexate
• Drug eruption
• Psoriasis
• Autoimmune disease