<p><strong>Myxedema</strong> (British English: <strong>myxoedema</strong>) is a skin and tissue disorder usually due to severe prolonged <strong><a title="Hypothyroidism" href="http://en.wikipedia.org/wiki/Hypothyroidism">hypothyroidism</a></strong>. Hypothyroidism can be caused by <a title="Hashimoto's thyroiditis" href="http://en.wikipedia.org/wiki/Hashimoto%27s_thyroiditis">Hashimoto's thyroiditis</a>, surgical removal of the <a title="Thyroid" href="http://en.wikipedia.org/wiki/Thyroid">thyroid</a>, and rarer conditions. Partial forms of myxedema, especially of the lower legs (called <a title="Pretibial myxedema" href="http://en.wikipedia.org/wiki/Pretibial_myxedema">pretibial myxedema</a>), occasionally occur in adults with <a title="Graves' disease" href="http://en.wikipedia.org/wiki/Graves%27_disease">Graves' disease</a>, a cause of hyperthyroidism; or also Hashimoto's thyroiditis without severe hypothyroidism.</p><p><table id="toc" summary="Contents" class="toc"> <tbody> <tr> <td> <div id="toctitle"> <h2>Contents&nbsp;</h2p> <span class="toctoggle">[<a class="internal" id="togglelink" href="javascript:toggleToc()">hide</ap>]</span></div> <ul> <li class="toclevelmw-1headline"><a hreffont size="http://en.wikipedia.org/wiki/Myxedema#Symptoms"><span class="tocnumber">1</span> <span class="toctext5">Symptoms</span></a> </li> <li class="toclevel-1"><a href="http://en.wikipedia.org/wiki/Myxedema#Causes"><span class="tocnumber">2</span> <span class="toctext">Causes</span></a> </li> <li class="toclevel-1"><a href="http://en.wikipedia.org/wiki/Myxedema#Treatment"><span class="tocnumber">3</span> <span class="toctext">Treatment</span></a> </li> <li class="toclevel-1"><a href="http://en.wikipedia.org/wiki/Myxedema#See_also"><span class="tocnumber">4</span> <span class="toctext"font>See also</span></a> </li> </ul> </td> </tr> </tbody></table><script type="text/javascript">//<![CDATA[ if (window.showTocToggle) { var tocShowText = "show"; var tocHideText = "hide"; showTocToggle(); } //]]></script></p><p><a id="Symptoms" name="Symptoms"></a></p><h2><span class="editsection">[<a title="Edit section: Symptoms" href="http://en.wikipedia.org/w/index.php?title=Myxedema&amp;action=edit&amp;section=1">edit</a>]</span> <span class="mw-headline">Symptoms</span></h2>

<li>Jelly-like infiltrations in <a class="mw-redirect" title="Subcutaneous" href="http://en.wikipedia.org/wiki/Subcutaneous">subcutaneous</a> tissues </li>

<li>Swollen <a class="mw-redirect" title="Subcutaneous" href="http://en.wikipedia.org/wiki/Subcutaneous">subcutaneous</a> tissue </li>

<li><a title="Constipation" href="http://en.wikipedia.org/wiki/Constipation">Constipation</a> </li>

<li><a class="mw-redirect" title="Deafness" href="http://en.wikipedia.org/wiki/Deafness">Deafness</a> </li> <li><a title="Hearing impairment" href="http://en.wikipedia.org/wiki/Hearing_impairment">Hearing impairment</a> </li> <li><a title="Carpal tunnel syndrome" href="http://en.wikipedia.org/wiki/Carpal_tunnel_syndrome">Carpal tunnel syndrome</a> </li>

<p><a id="Causes" name="Causes"></a>&nbsp;</p><h2p><span class="editsectionmw-headline">[<a title="Edit section: Causes" hreffont size="http://en.wikipedia.org/w/index.php?title=Myxedema&amp;action=edit&amp;section=25">editCauses</afont>]</span> <span class="mw-headline">Causes</span></h2p><p>Myxedema stemming from both the <a class="mw-redirect" title="Hyperthyroid" href="http://en.wikipedia.org/wiki/Hyperthyroid">hyperthyroid</a> and <a class="mw-redirect" title="Hypothyroid" href="http://en.wikipedia.org/wiki/Hypothyroid">hypothyroid</a> conditions, results from the accumulation of increased amounts of <a class="mw-redirect" title="Hyaluronic acid" href="http://en.wikipedia.org/wiki/Hyaluronic_acid">hyaluronic acid</a> and <a title="Chondroitin sulfate" href="http://en.wikipedia.org/wiki/Chondroitin_sulfate">chondroitin sulfate</a> in the <a title="Dermis" href="http://en.wikipedia.org/wiki/Dermis">dermis</a> in both lesional and normal skin. The mechanism that causes myxedema is still not yet understood, although animal model studies suggest that <a title="Thyroid" href="http://en.wikipedia.org/wiki/Thyroid">thyroid</a> <a class="mw-redirect" title="Hormones" href="http://en.wikipedia.org/wiki/Hormones">hormones</a> affect the <a title="Synthesis" href="http://en.wikipedia.org/wiki/Synthesis">synthesis</a> and <a title="Catabolism" href="http://en.wikipedia.org/wiki/Catabolism">catabolism</a> of <a class="mw-redirect" title="Mucopolysaccharides" href="http://en.wikipedia.org/wiki/Mucopolysaccharides">mucopolysaccharides</a> and <a title="Collagen" href="http://en.wikipedia.org/wiki/Collagen">collagen</a> by dermal <a class="mw-redirect" title="Fibroblasts" href="http://en.wikipedia.org/wiki/Fibroblasts">fibroblasts</a>. The fibroblasts in the <a title="Orbit (anatomy)" href="http://en.wikipedia.org/wiki/Orbit_%28anatomy%29">orbital</a> and <a class="new" title="Pretibial (page does not exist)" href="http://en.wikipedia.org/w/index.php?title=Pretibial&amp;action=edit&amp;redlink=1">pretibial</a> <a title="Dermis" href="http://en.wikipedia.org/wiki/Dermis">dermis</a> share <a class="mw-redirect" title="Antigenic" href="http://en.wikipedia.org/wiki/Antigenic">antigenic</a> sites that underlie the <a class="mw-redirect" title="Autoimmune" href="http://en.wikipedia.org/wiki/Autoimmune">autoimmune</a> process that causes <a class="mw-redirect" title="Grave's disease" href="http://en.wikipedia.org/wiki/Grave%27s_disease">Grave's disease</a>. This cross-reaction may contribute to the development of myxedema long after normal levels of thyroid hormones have been restored by treatment.</p><p><a id="Treatment" name="Treatment"></a>&nbsp;</p><h2p><span class="editsectionmw-headline">[<a titlefont size="Edit section: Treatment" href="http://en.wikipedia.org/w/index.php?title=Myxedema&amp;action=edit&amp;section=35">edit</a>]Treatment</span> <span class="mw-headline"font>Treatment</span></h2p><p>Treatment for myxedema is difficult. Systemic or <a class="new" title="Intralesional (page does not exist)" href="http://en.wikipedia.org/w/index.php?title=Intralesional&amp;action=edit&amp;redlink=1">intralesional</a> <a class="mw-redirect" title="Glucocorticoids" href="http://en.wikipedia.org/wiki/Glucocorticoids">glucocorticoids</a>, <a title="Topical" href="http://en.wikipedia.org/wiki/Topical">topical</a> <a class="mw-redirect" title="Glucocorticoids" href="http://en.wikipedia.org/wiki/Glucocorticoids">glucocorticoids</a> under <a title="Occlusion" href="http://en.wikipedia.org/wiki/Occlusion">occlusion</a> or high-dose <a class="mw-redirect" title="Intravenous" href="http://en.wikipedia.org/wiki/Intravenous">intravenous</a> <a class="mw-redirect" title="Immunoglobulin" href="http://en.wikipedia.org/wiki/Immunoglobulin">immunoglobulin</a> have been reported to offer some relief to patients. Treatment should follow correction of the original hyperthyroidism/hypothyroidism.</p><p><a id="See_also" name="See_also"></a>&nbsp;</p><h2p><span class="editsectionmw-headline">[<a titlefont size="Edit section: 5">See also" href="http://en.wikipedia.org/w/index.php?title=Myxedema&amp;action=edit&amp;section=4">edit</afont>]</span> <span class="mw-headline">See also</span></h2p><p>Severe hypothyroidism in a child is called <a title="Cretinism" href="http://en.wikipedia.org/wiki/Cretinism">Cretinism</a> -<br />