The coexistence of psoriasis vulgaris, Sjögren's syndrome, and Hashimoto's thyroiditis

Psoriasis, Psoriatic Arthritis, and Thyroid Autoimmunity

Psoriasis (PsO) is a chronic relapsing/remitting autoimmune skin disease, associated with an increased risk of other autoimmune disorders. Psoriatic arthritis (PsA) is a chronic inflammatory arthritis occurring approximately in 30% of PsO patients. Sporadic cases of association between PsO and autoimmune thyroid disorders (AITDs) have been reported. However, two different recent studies did not find any association between them. In patients with PsO and PsA, an association with AITD has been shown by most of the studies in adults, but not in the juvenile form. In PsA women and men, thyroid autoimmunity [positive antithyroid peroxidase (AbTPO) antibodies, hypoechoic thyroid pattern] and subclinical hypothyroidism were more prevalent than in the general population. An association has been shown also in patients with PsO, arthritis, and inflammatory bowel disease, who have more frequently AITD. A Th1 immune predominance has been shown in early PsO, and PsA, with high serum CXCL10 (Th1 prototype chemokine), overall in the presence of autoimmune thyroiditis. This Th1 immune predominance might be the immunopathogenetic base of the association of these disorders. A raised incidence of new cases of hypothyroidism, thyroid dysfunction, positive AbTPO, and appearance of a hypoechoic thyroid pattern in PsA patients, especially in women, has been shown recently, suggesting to evaluate AbTPO levels, thyroid function, and thyroid ultrasound, especially in PsA women. Thyroid function follow-up and suitable treatments should be performed regularly in PsA female patients at high risk (thyroid-stimulating hormone within the normal range but at the higher limit, positive AbTPO, hypoechoic, and small thyroid).

Current knowledge on psoriasis and autoimmune diseases

Psoriasis is a prevalent, chronic inflammatory disease of the skin, mediated by crosstalk between epidermal keratinocytes, dermal vascular cells, and immunocytes such as antigen presenting cells (APCs) and T cells. Exclusive cellular “responsibility” for the induction and maintenance of psoriatic plaques has not been clearly defined. Increased proliferation of keratinocytes and endothelial cells in conjunction with APC/T cell/monocyte/macrophage inflammation leads to the distinct epidermal and vascular hyperplasia that is characteristic of lesional psoriatic skin. Despite the identification of numerous susceptibility loci, no single genetic determinant has been identified as responsible for the induction of psoriasis. Thus, numerous other triggers of disease, such as environmental, microbial and complex cellular interactions must also be considered as participants in the development of this multifactorial disease. Recent advances in therapeutics, especially systemic so-called “biologics” have provided new hope for identifying the critical cellular targets that drive psoriasis pathogenesis. Recent recognition of the numerous co-morbidities and other autoimmune disorders associated with psoriasis, including inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus suggest common signaling elements and cellular mediators may direct disease pathogenesis. In this review, we discuss common cellular pathways and participants that mediate psoriasis and other autoimmune disorders that share these cellular signaling pathways.

Lambert-Eaton Myasthenic syndrome in a child with an autoimmune phenotype

We report on a child with a family history of autoimmune defects, who presented at the age of 3(1/2) years with alopecia and Graves disease. He subsequently developed vitiligo and psoriasis. At 9(1/2) years, he developed an autoimmune form of Lambert-Eaton Myasthenic syndrome (LEMS) with a significant elevation of glutamic acid decarboxylase (GAD) autoantibodies. Shortly thereafter he developed chronic urticaria. HLA associations were present for Graves disease, vitiligo, psoriasis, and IgA deficiency. There was also evidence of autoimmunity involving the pancreatic islet cells and gastric parietal cells.

Skin disorders and thyroid diseases

Thyroid disorders have a high prevalence in medical practice; they are associated with a wide range of diseases with which they may or may not share etiological factors. One of the organs which best show this wide range of clinical signs is the skin. This review is an attempt to approach most of the dermopathies reflecting several degrees of harmfulness, coming directly or indirectly from thyroid abnormalities, as well as to update current knowledge on the relationship between the thyroid and skin. We have proposed a primary classification of skin disorders, regarding thyroid involvement, into two main groups: 1) dermopathies associated with thyroid abnormalities, mainly with autoimmune thyroid diseases, like melasma, vitiligo, Sjogren's syndrome, alopecia, idiopathic hirsutism, pre-menstrual acne, bullous diseases, connective tissue diseases, hamartoma syndrome, atopy, leprosy and DiGeorge anomaly; and 2) dermopathies depending on the nature of the thyroid disorder, in which the evolution and outcome of the skin disorder depend on the thyroidal treatment in most cases, such as trophism and skin blood flow, myxedema, alopecia, onychodystrophy, hypo- and hyperhidrosis, xanthomas, intraepidermal bullae, carotenodermia, pruritus, flushing, pyodermitis, palmoplantar keratoderma, ecchymosis, etc. In some other cases, the skin disease which developed as a consequence of the thyroid abnormality can remain unaltered despite functional treatment of the thyroid problem, such as pretibial myxedema, thyroid acropachy and some cutaneous manifestations of multiple endocrine neoplasia types 2A and 2B.

Hashimoto's thyroiditis, Sjogren's syndrome and orbital lymphoma

A 69 year old Chinese housewife presented with periorbital puffiness, and dry eyes and mouth. Subsequent investigations confirmed the presence of Hashimoto's thyroiditis, Sjogren's syndrome and orbital lymphoma. This unusual combination is discussed with reference to previous publications.