Cutaneous mucinosis of infancy: a rare case of joint involvement

Cristina Morreale,D Bleidl ,Angela Rita Sementa,Clara Malattia

doi:10.1186/s12969-021-00590-6

Abstract

BackgroundPrimary cutaneous mucinosis are a heterogeneous group of diseases characterized by the deposition of glycosaminoglycans in the dermis and the follicles. These diseases are rare in children therefore their diagnosis and management are still challenging. Joint involvement has been reported in patients with secondary cutaneous mucinosis and, rarely, in primary mucinosis. We describe a case of Cutaneous Mucinosis of Infancy with joint involvement.Case presentationAn healthy 5-year-old boy showed acute arthritis of the left knee and left elbow confirmed by ultrasound. Laboratory tests were within normal range. Symptoms disappeared after a course of nonsteroid anti-inflammatory drugs. One year later, the knee swelling reappeared; juvenile idiopathic arthritis was diagnosed and intra-articular steroid injection was performed. Due to persistence of arthritis of the knee he was admitted to our hospital. On physical examination variable skin-colored lesions were observed, which had been in existence for over 2 years.We performed a skin biopsy that showed an interstitial mucine deposition in the reticular dermis. Cutaneous Mucinosis of Infancy was diagnosed.Discussion and conclusionsCutaneous Mucinosis of Infancy is a persistent dermatosis with benign prognosis and no treatment is generally required. Our case report is particularly interesting because it is the first in which joint involvement has been reported in CMI, a disorder that has so far been described as limited to skin involvement. Further studies will be necessary in order to clarify the pathogenesis of joint involvement in primary mucinosis.

Highlights

Primary cutaneous mucinosis are a heterogeneous group of diseases characterized by the deposition of glycosaminoglycans in the dermis and the follicles
Cutaneous Mucinosis of Infancy is a persistent dermatosis with benign prognosis and no treatment is generally required
Our case report is interesting because it is the first in which joint involvement has been reported in Cutaneous Mucinosis of Infancy (CMI), a disorder that has so far been described as limited to skin involvement

Summary

Discussion and conclusions

CMI is a persistent dermatosis characterized by the presence of asymptomatic and variably sized skin-colored to erythematous papules, plaques or single nodules, generally localized in the upper extremities and trunk, with benign prognosis [4, 5]. Our case report is interesting because it is the first in which joint involvement has been reported in association with CMI, a disorder that has so far been described as limited to skin involvement. Joint symptoms have been described in other forms of primary cutaneous mucinosis, such as SHJCM, in association with other systemic symptoms like fever, myositis and lymphocytosis [6, 7]. Some interesting in vitro studies have revealed immunologic functional characteristics of specific glycosaminoglycans (GAGs): low molecular weight (LMW) hyaluronan (HA) activates. CMI is a rare condition and few cases have been described. Further studies will be necessary in order to better define the clinical findings of different forms of cutaneous mucinosis in children.

Background