Widespread granulomatous dermatitis of infancy: an early sign of Blau syndrome.
BACKGROUND
Pediatric sarcoidosis has traditionally been divided into 2 distinct groups: (1) school-aged children and adolescents with frequent involvement of the lungs and mediastinal lymph nodes (similar to adult sarcoidosis) and (2) infants and preschoolers with the triad of arthritis, uveitis, and a cutaneous eruption of discrete small papules, referred to as early-onset sarcoidosis. Blau syndrome, a rare autosomal dominant genodermatosis caused by mutations in the NOD2 (nucleotide-binding oligomerization domain 2) gene, has been considered as the familial form of early-onset sarcoidosis.


METHODS
A 9-month-old boy developed an asymptomatic eruption of 1- to 2-mm, red-brown to pinkish tan, flat-topped papules on the face, trunk, and extremities. There was no evidence of ocular involvement or arthritis. The skin lesions were characterized histologically by noncaseating granulomas in a periadnexal distribution within the dermis. A family history of uveitis supported a diagnosis of Blau syndrome, and analysis of the NOD2 gene revealed a heterozygous gain-of-function missense mutation (Arg334Trp) that has previously been detected in Blau syndrome kindreds.


CONCLUSIONS
We draw attention to granulomatous dermatitis as an early manifestation of Blau syndrome and highlight emerging molecular evidence that this heritable autoinflammatory disorder and early-onset sarcoidosis represent a single disease entity.
Schaffer
Julie V
JV
Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York 10016, USA. schafj04@med.nyu.edu
Chandra
Pranil
P
Keegan
Brian R
BR
Heller
Patricia
P
Shin
Helen T
HT
D003872:Dermatitis / Q000473:pathology*; D006099:Granuloma / Q000473:pathology*; D006801:Humans; D007223:Infant; D008297:Male; D009154:Mutation; D053473:Nod2 Signaling Adaptor Protein / Q000235:genetics; D010375:Pedigree; D012507:Sarcoidosis / Q000235:genetics / Q000473:pathology*; D012871:Skin Diseases / Q000235:genetics / Q000473:pathology; D013577:Syndrome
C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein