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Endocrine effects on the skin - Pathology (view source)
Revision as of 10:50, 31 July 2008
, 10:50, 31 July 2008New page: {{toplink |backcolour = FAFAD2 |linkpage =Endocrine System - Pathology |linktext =Endocrine System |maplink = Endocrine System (Content Map) - Pathology |pagetype =Pathology }} <br> The en...
{{toplink
|backcolour = FAFAD2
|linkpage =Endocrine System - Pathology
|linktext =Endocrine System
|maplink = Endocrine System (Content Map) - Pathology
|pagetype =Pathology
}}
<br>
The endocrine system typically has effects on the hair growth cycle so alopecia is a common finding. Many types of [[Skin - metabolic|endocrine skin disease]] cause similar pathology.
===The hair growth cycle===
<p>Hair follicles grow in repeated cycles in a mosiac pattern so that the whole hair coat isn't lost at one time.
*'''Anagen''': Growth phase.<br>The majority of hair follicles will be in this phase. The hair grows in length.
*'''Catagen''': Transition phase.<br>The dermal papilla is broken away and the follicle shrinks.
*'''Telogen''': Resting phase.<br>The hair doesn't grow but stays attached while the dermal papilla is resting.</p>
<p>After telogen the follicle re-enters anagen and the dermal papilla reattaches to the base of the follicle. If the old hair has not already epilated it will be pushed out by the new growing hair.</p>
===Pathogenesis===
<p>General skin changes seen with endocrine disease include:
*Hypotrichosis.
*Alopecia; usually bilaterally symmetric and non-pruritic.
*Pigment disturbance.
*Seborrhoea.</p>
<p>Histologically many of the follicles will be in telogen where the haircoat is easily epilated and then fails to regrow. This is why alopecia occurs over areas of friction (trunk face etc) while the legs and tail are spared. Follicular and epidermal atrophy may be evident along with atrophy of the adnexa E.g sebaceous atrophy.</p>
Specific changes associated with disease:
[[Image:Flame follicles.jpg|right|thumb|125px|<small><center>'''Flame Follicles'''. Courtesy of A. Jefferies</center></small>]]
*[[Thyroid Gland - Pathology#Hypothyroidism|'''Hypothyroidism''']]: Mucin within the dermis; myxoedema.
*[[Adrenal Glands - Pathology#Adrenal_Hyperfunction|'''Hyperadrenocorticism''']]: [[Adrenal Glands - Pathology#Pathophysiology_2|Calcinosis cutis]] and dermal thinning.
*[[Pituitary Gland - Pathology#Pituitary_Hypofunction|'''GH deficiency''']]: Decreased dermal elastin and catagen follicles ('''Flame follicles''').
|backcolour = FAFAD2
|linkpage =Endocrine System - Pathology
|linktext =Endocrine System
|maplink = Endocrine System (Content Map) - Pathology
|pagetype =Pathology
}}
<br>
The endocrine system typically has effects on the hair growth cycle so alopecia is a common finding. Many types of [[Skin - metabolic|endocrine skin disease]] cause similar pathology.
===The hair growth cycle===
<p>Hair follicles grow in repeated cycles in a mosiac pattern so that the whole hair coat isn't lost at one time.
*'''Anagen''': Growth phase.<br>The majority of hair follicles will be in this phase. The hair grows in length.
*'''Catagen''': Transition phase.<br>The dermal papilla is broken away and the follicle shrinks.
*'''Telogen''': Resting phase.<br>The hair doesn't grow but stays attached while the dermal papilla is resting.</p>
<p>After telogen the follicle re-enters anagen and the dermal papilla reattaches to the base of the follicle. If the old hair has not already epilated it will be pushed out by the new growing hair.</p>
===Pathogenesis===
<p>General skin changes seen with endocrine disease include:
*Hypotrichosis.
*Alopecia; usually bilaterally symmetric and non-pruritic.
*Pigment disturbance.
*Seborrhoea.</p>
<p>Histologically many of the follicles will be in telogen where the haircoat is easily epilated and then fails to regrow. This is why alopecia occurs over areas of friction (trunk face etc) while the legs and tail are spared. Follicular and epidermal atrophy may be evident along with atrophy of the adnexa E.g sebaceous atrophy.</p>
Specific changes associated with disease:
[[Image:Flame follicles.jpg|right|thumb|125px|<small><center>'''Flame Follicles'''. Courtesy of A. Jefferies</center></small>]]
*[[Thyroid Gland - Pathology#Hypothyroidism|'''Hypothyroidism''']]: Mucin within the dermis; myxoedema.
*[[Adrenal Glands - Pathology#Adrenal_Hyperfunction|'''Hyperadrenocorticism''']]: [[Adrenal Glands - Pathology#Pathophysiology_2|Calcinosis cutis]] and dermal thinning.
*[[Pituitary Gland - Pathology#Pituitary_Hypofunction|'''GH deficiency''']]: Decreased dermal elastin and catagen follicles ('''Flame follicles''').