Disorders of autoimmune pathogenesis occur with increased frequency in patients with a history of another autoimmune disease. The causes for the onset and manifestation of associated diseases are various: genetic predisposition, shared pathogenic mechanisms, and others are of unknown nature [
5]. A subject with one autoimmune disease has 25 % chance to get another autoimmune disease [
6]. In our case the patient suffering from CD was diagnosed to have other two different autoimmune diseases (SLE and HT). Evidences show that in patients with CD occurrence of thyroid dysfunction is up to 10 % of cases, and risk of thyroid disease is threefold higher as compared to controls [
7]; on the other hand, the prevalence of CD is higher in patients with autoimmune thyroid disease, with a prevalence ranging from 1.2 to 9.3 % [
7‐
9]. Similarly, thyroid disease appears to be more frequent in SLE patients than in the general population. Studies reported that SLE is associated to hypothyroidism with a range of variability from 4 to 21 % and patients diagnosed for HT are more prone to develop SLE than normal controls [
10]. An association between CD and SLE has been recorded in some case reports [
11,
12], with a recent study suggesting that individuals with CD are at threefold increased risk of SLE, but absolute risk is low [
11]. Furthermore, it has been shown that SLE may develop later in the clinical course of CD even after a small bowel biopsy response to gluten free therapy [
13]. However, to the authors’ knowledge, only one study reported a case of MAS in a young girl suffering from CD, HT and SLE [
14]. It is interesting that in our case the association among the three autoimmune diseases was observed in a young man, being the autoimmune disorders more prevalent in women (including CD and SLE) [
15]. Moreover, the patient had a clinical history of psychiatric symptoms presented as he was 18 years old that could be likely considered as an early manifestation of SLE. It is known that SLE may cause a broad range of neurological and psychiatric symptoms that can precede the onset of lupus or occur at any time during the course of the disease. However, the psychosis is not a common feature in SLE, and the reported prevalence of lupus psychosis varies from 0 to 11 %. Recently, the diagnosis of lupus psychosis at the moment of the onset of the disease has been described in one-third of the cases of a large series of SLE patients, but it has been observed that it usually occurs within the context of florid activity of the disease, mainly associated with cutaneous or haematological manifestations [
16]. It has also to be stressed that several psychiatric symptoms and disorders, such as anxiety disorders, depressive and mood disorders, attention deficit hyperactivity disorder (ADHD) and schizophrenia [
17] have been associated with CD, even if the research on the relationship of these psychiatric disorders to CD is limited. On this view, the psychosis in our patient could also be an early manifestation of the CD rather than of SLE. In conclusion, our case report is of interest upon different notes. First, the rare association of the three autoimmune disorders described: CD has been reported as part of MAS in association with HT and SLE just once in literature and is not included in the classification of MAS, so that our patient can be classified only partially within MAS Type 3; second, the appearance of these three autoimmune diseases in a man and finally the atypical onset of the diseases with psychiatric symptoms that can be related either to CD or to SLE. Moreover, this case of MAS highlights the importance to make a good clinical surveillance in patients with one autoimmune disorder because they have a higher risk of developing another autoimmune disease even rarely associated with the first one.