Erythema nodosum and pernicious anemia

Area of Science:

• Dermatology
• Hematology
• Internal Medicine

Background:

• Erythema nodosum (EN) is an inflammatory condition characterized by tender, red nodules, typically on the lower legs.
• Pernicious anemia is an autoimmune condition leading to vitamin B12 deficiency.
• The association between EN and pernicious anemia is uncommon but warrants clinical consideration.

Observation:

• A patient presented with classic symptoms of erythema nodosum.
• Diagnostic workup revealed findings consistent with pernicious anemia and vitamin B12 deficiency.
• This presentation prompted a review of the infrequent link between these two conditions.

Findings:

• The case illustrates a rare instance where erythema nodosum may be associated with pernicious anemia.
• Vitamin B12 deficiency, secondary to pernicious anemia, was identified as a potential contributing factor.
• The diagnostic pathway and clinical management are discussed.

Implications:

• Clinicians should consider pernicious anemia in the differential diagnosis of erythema nodosum, especially in persistent or unusual cases.
• Early identification of vitamin B12 deficiency can prevent serious neurological complications.
• This association underscores the systemic nature of some dermatological presentations.