Remission of acanthosis nigricans, hypertrichosis, and Hashimoto's thyroiditis with thyroxine replacement

Acanthosis nigricans: A review

BACKGROUND

Acanthosis nigricans (AN) is a cutaneous disorder characterized by symmetric velvety hyperpigmented plaques on intertriginous areas like axilla, neck, inframammary, and groin.

AIMS

To summarize the pathophysiology and classification of AN, provide an update of diagnostic testing strategies, and describe the current therapeutic options described so far in the literature for this disease.

METHODS

A comprehensive english language literature search across multiple databases (PubMed, EMBASE, MEDLINE, and Cochrane) for keywords (alone and in combination) was performed. MeSH as well as non-MeSH terms such as "acanthosis nigricans," "classification," "pathophysiology," "diagnosis," "treatment," "topical drugs," "systemic drugs," "chemical peeling," and "lasers" were taken into consideration.

RESULTS

The pathophysiology of AN revolves around a multifactorial stimulation of proliferation of epidermal keratinocytes and dermal fibroblasts. Various types of AN include benign, obesity-associated, syndromic, malignant, acral, unilateral, medication-induced, and mixed-type. Homeostasis model assessment-insulin resistance (HOMA-IR) is a good tool for assessment of insulin resistance. Management involves general measures (weight reduction and addressing the underlying cause, if any), topical drugs (retinoids, vitamin D analogs, and keratolytics), oral drugs (retinoids and insulin sensitizers), chemical peels (trichloroacetic acid), and lasers (Long pulsed alexandrite, fractional 1550-nm erbium fiber, and CO₂ ).

CONCLUSION

Acanthosis nigricans is a treatable condition; however, complete cure and disappearance of lesions are difficult to achieve. Weight reduction is the most scientific and practical management strategy. Long-term studies and further research is warranted in the pathophysiology and treatment of this common condition.

A case of generalized acanthosis nigricans with positive lupus erythematosus-related autoantibodies and antimicrosomal antibody: autoimmune acanthosis nigricans?

Acanthosis nigricans (AN) is a hyperpigmented keratotic skin lesion known to be associated with malignant disease and endocrinopathy. We report a very rare case of generalized AN with Sjögren's syndrome- and systemic lupus erythematosus-like features but without type B insulin resistance. Neither internal malignancy nor other endocrinological disorders, including glucose intolerance, were detected during a 10-year clinical course with benign diffuse papillomatosis extending from the mucosa of the larynx to the esophagogastric junction. The case was complicated with chronic thyroiditis and interstitial pneumonia, which were not treated with any medication. AN skin lesions and mucosal papillomatosis regressed with oral cyclosporine A, accompanied by the lowering of autoantibody titers. This is the first report of generalized AN involving an area from the mucosa of the larynx to the esophagogastric junction accompanied by autoimmune manifestations which responded to systemic immunosuppressive therapy.

Acquired ichthyosis and hypertrichosis due to autoimmune thyroiditis: therapeutic response to thyroxine replacement

Thyroid diseases may be associated with a wide variety of dermatologic disorders. We report a 15-year-old girl with acquired ichthyosis and hypertrichosis associated with hypothyroidism resulting from autoimmune thyroiditis. Her skin lesions progressively resolved after 8 months of replacement therapy with L-thyroxine. This result supports the hypothesis that hypothyroidism in our patient can be directly related to the pathogenesis of acquired ichthyosis and hypertrichosis.

Familial juvenile autoimmune hypothyroidism, pituitary enlargement, obesity, and insulin resistance

The proband, a 9-year-old Hispanic female, presented with hair loss, strabismus, and weight gain. On magnetic resonance imaging (MRI) she was found to have severe primary hypothyroidism and a large pituitary mass. In addition, acanthosis nigricans, obesity, and hyperinsulinism were observed. Findings were similar in three of four siblings. Thyroid peroxidase antibodies were detected in the father and three of four siblings. Although all family members were obese, and hyperinsulinemia with high proinsulin and C-peptide was found in all except one sibling, only the mother and one child had overt type 2 diabetes mellitus. Because of the unusual association of autoimmune thyroid disease, insulin resistance and obesity rather than insulin deficiency, we searched for possible genetic abnormalities. The HLA haplotypes did not cosegregate with autoimmune thyroid disease or insulin resistance. Mutational analysis of known obesity genes was done. Leptin was not deficient, and sequencing of the proband's DNA showed no mutations in the perixisome proliferator activated receptor (PPAR)-gamma, PPAR-gamma(2), PPAR-alpha or melanocortin 4 receptor genes. Maternally inherited diabetes and deafness was ruled out since no mutations were found in mitochondria DNA. Insulin receptor antibodies were not detected. In conclusion, the remarkably high incidence of childhood autoimmune hypothyroidism, pituitary enlargement, insulin resistance and obesity in this family is not linked to known HLA types or known gene defects.

Autoimmune thyroid diseases: etiology, pathogenesis, and dermatologic manifestations

Autoimmune thyroid disease (AITD) including Graves' disease, Hashimoto's thyroiditis, and idiopathic hypothyroidism (atrophic Hashimoto's thyroiditis) is of vital concern to the dermatologist. This article reviews the cutaneous manifestations of Graves' disease and Hashimoto's thyroiditis. Recognition of dermatologic manifestations of AITD may alert practitioners to investigate for these disorders. The immune response involved in the pathogenesis of AITD is detailed. Current understanding of the role of genetic and environmental factors, antigens, and apoptosis are elaborated. The future holds exciting insight into the etiology, pathogenesis, and treatment of AITD.

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.

Acanthosis nigricans

Acanthosis nigricans is a mucocutaneous eruption that occurs in a strikingly exuberant form as a marker for a highly malignant and rapidly fatal internal cancer. Recently, it has been recognized that acanthosis nigricans may also be a relatively common marker for increased long-term risk of the less dramatic but potentially serious systemic disorders associated with insulin resistance and compensatory increased insulin secretion.

Cutaneous manifestations of thyroid disease

Cutaneous manifestations of thyroid disease are protean in nature and affect all age groups. This review focuses on normal thyroid gland physiology, specific cutaneous/thyroid lesions such as the thyroglossal duct cyst and metastatic thyroid malignancies, nonspecific cutaneous alterations of the hyperthyroid and hypothyroid states, and the numerous associations of thyroid disease with other cutaneous and/or systemic disorders.