Violaceous Maculopapular Rash in a Newborn: Congenital Rubella Syndrome

Abstract

Congenital rubella syndrome involves a configuration of systemic and cutaneous manifestations in a neonate due to in utero infection caused by the rubella virus. The case of a preterm neonate with blueberry muffin lesions and classical as well as rare systemic features of congenital rubella syndrome is reported.

What was known?

• Dermal erythropoiesis is caused by an array of conditions, congenital rubella being one of them

• The congenital rubella infection can have cardiovascular, ocular and a wide range of systemic manifestations along with cutaneous involvement in the form of thrombocytopenic purpura, maculopapular rash, and less frequently blueberry muffin lesion.

Introduction

Infection by rubella virus in early pregnancy leads to a constellation of devastating effects on multiple organs characteristically called as Gregg syndrome. Cutaneous manifestations are varied and infrequent but the presence of dermal erythropoiesis indicates a severe disease.[1]

We report a case of a preterm newborn with microcephaly, hepatosplenomegaly along with violaceous lesions all over the body.

Case Report

Dermatological opinion was sought by neonatal care unit for a preterm male newborn with a generalized violaceous skin rash. The baby was delivered at 35 weeks of gestation after an emergency caesarian section performed for premature rupture of membranes. There were no significant antenatal complaints in the mother.

On examination, the neonate was tachypnoeic but acyanotic and had microcephaly (head circumference 30 cm, less than third centile), and low birth weight (2 kg). Systemic examination revealed hepatosplenomegaly and a pansystolic murmur on auscultation. Ophthalmological examination was normal. On cutaneous examination, there were multiple, discrete, 0.5 × 0.5 to 2 × 1 cm sized, violaceous macules and barely palpable nodules found predominantly over the face and upper trunk [Figure 1]. Palms, soles and mucosae were spared. Based on cutaneous manifestations, a diagnosis of blueberry muffin baby syndrome was made.

Figure 1.

Purple macules and barely palpable nodules over the body

Blood investigations showed severe thrombocytopenia (platelet count: 17,000/mm³), raised prothrombin (test: 21.3 s, control: 11.7 s) and activated partial thromboplastin time (test: 180 s, control: 30) with INR of 1.82. Skeletal survey revealed metaphyseal lucencies of long bones and enlarged right atrium [Figure 2]. A small patent ductus arteriosus (PDA) of 2 mm was detected on echocardiography, whereas electrocardiogram was normal. Ultrasonography of the head showed linear echogenic foci, suggestive of calcification in the chordothalamic region.

Figure 2.

Skeletal survey showing metaphysial lucencies of long bones

Histopathology from a cutaneous nodule showed several ill-defined nodules of extramedullary hematopoiesis in the dermis, reaching up to subcutis suggestive of blue berry muffin lesions [Figure 3]. Serology of the neonate showed the presence of IgM antibody (42.20 IU/ml) to rubella virus. The mother was also found to be positive for Rubella IgM, 79.70 IU/ml, and cytomegalovirus IgG, 209 IU/ml. Rest of the serological tests for TORCH (toxoplasma, cytomegalovirus, herpes virus) and Venereal Disease Research Laboratory (VDRL) were non-reactive in both mother and the neonate. On the basis of the above findings, a final diagnosis of congenital rubella syndrome (CRS) was made.

Figure 3.

High power view (×100) of a skin biopsy (H and E stain) showing nucleated red blood cells, megakaryocytes and metamyelocytes suggestive of dermal erythropoiesis

Discussion

In this era of widespread vaccination, rubella still accounts for a high number of intrauterine infections in the developing countries. In an Indian study, 1-15% of all infants, suspected to have intra-uterine infection, had laboratory evidence of CRS.[2] Spectrum of CRS includes ocular abnormalities (cataracts, retinopathy, microphthalmos, glaucoma), sensorineural deafness, neurological defects (microcephaly, motor defects, mental retardation), cardiovascular abnormalities (PDA, ventricular septal defect, aortic stenosis), genitourinary and bone defects.

Cardiac abnormalities occur in 50% of the infants. Our case had PDA which is the most common cardiac defects observed in CRS.[3] The neonate had bone involvement and hepatosplenomegaly that have been reported only in 10-20% of these cases.[4] The osseous lesions present as transverse radiolucent zones and longitudinal bands of demineralization, which appear because of abnormal mineralization.[5] Rare features of microcephaly and brain calcification[4] were also observed in our case.

The cutaneous findings of CRS include a thrombocytopenic purpura, adult like maculopapular rash and less frequently blueberry muffin lesions. Only 5% of the CRS cases manifest with extramedullary dermal erythropoiesis as seen in this case.[4]

The exact etiopathogenesis of blueberry muffin lesions is still not known.[6] Numerous causes including the TORCH syndrome, hematological and neoplastic disorders have been described. Usually present at birth, clearing of the lesions mostly occurs by 3 to 6 weeks.[7] Extracutaneous signs and symptoms depend on the cause and can be severe. Thus, these neonates should be thoroughly worked up to rule out the underlying systemic disease and its extent. Prognosis of Blueberry muffin syndrome is thus variable, although dermal erythropoiesis is usually associated with severe disease.[1,4]

We attribute our blue berry muffin syndrome to congenital rubella infection. No specific therapy for congenital rubella has been established, so treatment is primarily supportive. We emphasize the importance of universal rubella immunization especially in females of reproductive age group to prevent the mortality and disability arising out of the congenital rubella infection.

What is new?

• Blueberry muffin lesions are a rare presentation of congenital rubella syndrome and portends a poor prognosis

• Rare but characteristic osseous and hepatic involvement is reported in this case.