Diagnostic Puzzle: test your skills

A 3-month-old boy presented to our clinic with several well-defined erythematous and annular plaques with indurated borders located on the face appearing 3 weeks post-partum.


Initial Presentation: A baby with red plaques on the face

Description: A 3-month-old boy presented to our clinic with several well-defined erythematous and annular plaques with indurated borders located on the face appearing 3 weeks post-partum. Histological examination showed a vacuolar interface dermatitis with dermal oedema and periadnexal infiltrate of lymphocytes.

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The 3-month-old boy was brought by his mother to our clinic who had noticed that her child had developed several round red lesions on his face (figure). She said that the problem had begun 3 weeks post-partum. The baby had been born at full term following an uncomplicated pregnancy. The patient’s mother was fit and well, with no medical history of noteโ€”specifically she did not report any previous infections, or dermatological or autoimmune diseases.

What is the most likely diagnosis?

  • Sweet syndrome
  • Atopic eczema
  • Neonatal lupus erythematosus
  • Cutaneous sarcoidosis

Answer: Neonatal lupus erythematosus

Breakdown: The baby had been seen by another dermatologist when he was 10 weeks old and given topical antifungal treatmentโ€”miconazole creamโ€”and a low potency topical corticosteroid creamโ€”hydrocortisoneโ€”which had no effect after a 2-week trial.

On examination, we found six, well defined, erythematous annular plaques, with indurated borders, on the baby’s face. We found no other abnormalities: the baby’s temperature was normal, his heart rate was 138 beats per min, and the respiratory rate was 36 breaths per min.

Histopathological examination of a biopsy sample of the plaque on the face showed a vacuolar interface dermatitis with dermal oedema and a periadnexal infiltrate of lymphocytes (figure). Laboratory blood tests showed that both the mother and child were positive for antibodies against extractable nuclear antigen. They were also positive for anti-Sjรถgren’s syndrome type A (SSA) and anti-Sjรถgren’s syndrome type B (SSB) antibodies. The erythrocyte sedimentation rate was 11 mm per h, the C-reactive protein concentration was 0ยท6 mg/L. The white cell count was 13ยท85โ€ˆร—โ€ˆ109 per Lโ€”the neutrophil count was 1ยท47โ€ˆร—โ€ˆ109 per L, eosinophils 0ยท18โ€ˆร—โ€ˆ109 per L, basophils 0ยท02โ€ˆร—โ€ˆ109 per L, lymphocytes 10ยท58โ€ˆร—โ€ˆ109 per L, and monocytes 1ยท60โ€ˆร—โ€ˆ109 per L. Both liver and kidney function tests were normal.

Taken together with the findings of the biopsy, we diagnosed neonatal lupus erythematosus.

Given that heart abnormalities are associated with the condition, we referred the baby to a paediatric cardiologist who requested an electrocardiogram which showed findings consistent with first-degree atrioventricular block.

3 months later at a follow-up appointment, all the baby’s skin lesions had resolved without any scarring.

Finally, again given the diagnosis and the positive antinuclear antibodies, we referred the patient’s mother to a rheumatologist who diagnosed Sjรถgren’s syndrome.

Neonatal lupus erythematosus is a passively acquired, self-limiting, autoimmune disease thought to be caused by the transplacental passage of anti-SSA and anti-SSB antibodies from mother to fetus: the skinโ€”and more importantlyโ€”the heart are particularly affected. In approximately half the cases, the mothers are asymptomatic at time of presentation. The cutaneous manifestations in the baby usually develop within the first few weeks of lifeโ€”typically appearing on the scalp and periorbital areas. The association of the skin lesions with positive anti-SSA and anti-SSB tests in both mother and baby is well recognised, and a skin biopsy is not necessarily required to make the diagnosis. The important complication of congenital heart blockโ€”which usually develops in utero and generally resolvesโ€”is rare and found in approximately 2% of pregnant women with anti-SSA or anti-SSB antibodies. The skin manifestations in neonatal lupus spontaneously resolve after 4โ€“6 months.

Source: All content for this โ€œDiagnostic Puzzleโ€ was sourced from The Lancet. The article was written by Sayed Meelad Habib, PhD, and Prof Maarten H Vermeer, MD, both from from Leiden University Medical Center, Leiden 2333 ZA, Netherlands.

Original article is available at:

https://www.thelancet.com/doi/story/10.1016/pic.2020.10.30.108552

and

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32176-0/fulltext

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