Sarcoidosis-like Skin Lesions as the First Manifestation of Ataxia-Telangiectasia

Abstract

Ataxia-telangiectasia is a rare autosomal recessive disorder that is difficult to diagnose due to its unpredictable presentation. It is characterized by cerebellar degeneration, telangiectasias, immunodeficiency, frequent pulmonary infections, and tumors. Immune system abnormalities manifest as disruptions in both cellular and humoral immunity. The most common findings include decreased levels of immunoglobulin classes (IgA, IgM, IgG, and IgG subclasses) and a reduced number of T and B lymphocytes. A four-year-old girl was initially evaluated and treated for skin lesions that presented as crusts spreading across her body. She was monitored by a pulmonologist due to frequent bronchial obstructions. Over time, she developed bilateral scleral telangiectasia, saccadic eye movements, and impaired convergence. Her gait was wide-based and unstable, with truncal ataxia and a positive Romberg sign. Laboratory tests revealed decreased immunoglobulin G levels, subclass IgG4 levels, elevated alpha-fetoprotein, and a reduced number of T and B lymphocytes. Brain magnetic resonance imaging showed cerebellar atrophy. Whole-exome sequencing identified heterozygous variants c.1564-165del, p.(Glu5221lefsTer43), and c.7630-2A>C in the serine/threonine-protein kinase ATM (ataxia-telangiectasia mutated) gene, confirming the diagnosis of ataxia-telangiectasia. Following diagnosis, treatment with intravenous immunoglobulin replacement was initiated along with infection prevention and management. The goal of this case report is to raise awareness of the atypical initial presentation that may lead to a diagnostic delay. We emphasize the importance of considering ataxia-telangiectasia in the differential diagnosis, even when classical neurological signs are not yet evident.

Keywords: ataxia-telangiectasia; cerebellar degeneration; chronic granulomatous skin disease; immunodeficiency.

Figure 1

Cutaneous granulomatous lesions on the lateral and posterior part of the upper left arm (A) and on the anterior part of the right thigh (B) clinically mimicking sarcoid-like dermatoses. The lesions presented as erythematous to livid firm nodules with central desquamation. Images were taken on the same day during the same stage of the disease.

Figure 2

Chronic granulomatous dermatitis and lobular panniculitis. (A) Microphotography of skin biopsy with granulomatous inflammation in dermis and in subcutaneous adipose tissue (HE × 50). (B) Detail of granuloma with giant cell (HE × 200). the arrow represents a granuloma with giant cell. (C) Granulomatous panniculitis (HE × 200).

Figure 3

T2-weighted MRI sequences of the brain demonstrate bilateral cerebellar hemispheric and vermis atrophy (B1,B2) in comparison to prior imaging performed three years before, when these structures appeared normal (A1,A2). The red arrow represents cerebellar athrophy.