Clinical and immunological characteristics of patients with undifferentiated connective tissue disease and dominating skin manifestation

Introduction
Undifferentiated connective tissue disease (UCTD) is characterized by presence of clinical and serological symptoms suggesting an autoaggressive systemic disease, while not meeting the criteria for diagnosing a defined entity. Over 50% of patients show skin lesions, which require dermatologic consultations.

Objective
To present clinical and immunological characteristics of patients with undifferentiated connective tissue disease.

Material and methods
Sixty patients were selected from all hospitalized at the Department of Allergy and Immunology and Department of Dermatology of the University Hospital in Krakow, Poland. The basis for selection was the diagnosis of “other overlap syndromes” (ICD-10 M35.1). All patients presented with symptoms suggesting connective tissue diseases and had circulating antinuclear antibodies.

Results
Ninety percent of the patients were women (median age of all group: 55 years). The most common skin and systemic symptoms as well as abnormalities in laboratory tests were the following: hypersensitivity to UV radiation (55%), arthralgia (55%), and moderate leukopenia (17%). Subclinical pulmonary fibrosis was revealed in 12 out of 60 (20%) patients. Forty-seven percent of the patients did not require systemic treatment. The other patients were most often administered glucocorticosteroids (43%) and hydroxychloroquine (13%). The statistical analysis showed dependence between the Raynaud’s syndrome and a sixfold increase in risk of co-occurring disorders in gastrointestinal motility, and between symptoms of Sjögren’s syndrome and a fivefold increase in chances for co-occurring pulmonary fibrosis (p < 0.05).

Conclusions
Undifferentiated connective tissue disease in most patients has a mild course and does not require systemic treatment. However, the disease is associated with a significant risk of progressing to a defined connective tissue disease. When taking care of a patient with an undifferentiated connective tissue disease it is important to know the prognosis, the most common clinical symptoms and a possible co-occurrence of particular symptoms, what will direct further diagnostics and follow-up.