Page 241 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 9-1 Genodermatoses and Syndromes
ADDISON’S DISEASE

Pigmentation of the gingival
Addison’s disease (chronic primary adrenocortical and labial mucosa
insufficiency) occurs when the adrenal gland has lost
most of its functional capacity. Addison’s disease can
be caused by many different disease states that inhibit Generalized skin
the functioning of the adrenal gland. The adrenal hyperpigmentation
gland has a massive reserve capacity, and clinical mani-
festations of chronic adrenal insufficiency are not seen
until the bilateral glands have lost at least 90% of their Darkening of hair
ability to produce adrenal hormones. Autoimmune
destructive atrophy of the adrenal glands is the most
common cause of Addison’s disease. Infectious pro- Freckling Autoimmune with cortical
cesses can cause destruction of the adrenal gland, with atrophy 80% of cases
tuberculosis one of the more common causes of chronic
adrenal gland insufficiency. Most cases of acute adrenal Areas of
gland destruction are caused by bacteria (i.e., meningo- vitiligo Hypotension
coccal disease).
Clinical Findings: Males and females are equally
affected. The first symptoms are lethargy and general- Pigment
ized malaise. These symptoms may not be apparent accentuation
until the affected patient undergoes a major stressful at nipples,
event, such as infection, which can lead to a prolonged at friction
disease course and a prolonged convalescence. Patients areas
have excessive nervousness and may show emotional
lability superimposed on periods of depression. Fatigue
and weakness can be severe, to the point where even
speaking causes fatigue. Weight loss and evidence of Pigment
dehydration are present in most cases. Hypotension is concentration
frequently seen, and a small heart shadow is seen on in skin creases Tuberculosis of adrenal
chest radiography. and in scars glands 10% of cases
Cutaneous effects are always found in chronic
primary adrenal insufficiency. Pigmentation is seen in Loss of
many regions of the body and appears to occur in areas pubic and
of friction, such as along the waist line and on elbows axillary hair
and knees. This is typically a generalized “bronze pig-
mentation,” but it is accentuated in the groin, nipples,
and scrotum. The palmar and plantar creases are accen- Loss of weight,
tuated. Hyperpigmentation may be prominent within emaciation: anorexia,
previous scars. Vitiligo may be present in conjunction vomiting, diarrhea
with autoimmune adrenal insufficiency. Increased pig-
mentation of hair is seen, but this may be subtle and
may occur slowly. Pigmentary alterations of the gingival Other causes:
and labial mucosa may also be seen. Pigmentary anoma- Muscular Metastatic disease
lies are not seen in secondary adrenal insufficiency, weakness Infections
which is caused by pituitary deficiency. Adrenal hemorrhage
Body hair is dramatically decreased, with near loss of Adrenoleukodystrophies
axillary and pubic hair. The hair loss is more pronounced Congenital adrenal hypoplasia
in females, because males still produce androgens, pri- Bilateral adrenalectomy
marily in the unaffected testes. Serum testing shows Drug-induced causes
hyperkalemia and hyponatremia, with a low cortisol
level. The diagnosis is confirmed by intravenously
injecting a synthetic corticotropin and evaluating the The fingernails
adrenal gland’s response by measuring cortisol levels may show
after the injection. In patients with Addison’s disease, linear bands
(melanonychia)
the serum cortisol level is not increased by stimulation of darkening
testing. arising from
Histology: Skin biopsies are not helpful in making the the nail matrix.
diagnosis and are rarely performed. A normal number
of melanocytes are present, with an increased amount
of melanin pigment in the epidermis.
Pathogenesis: The adrenal glands are responsible for seen in Addison’s disease are directly related to increased Addison’s disease is seen frequently in association
making cortisol, aldosterone, and the 17-ketosteroiods. release of MSH. The increase in MSH causes pigment with other autoimmune endocrine disorders such as
When the adrenal glands no longer are able to produce production by melanocytes in skin, hair, and mucous diabetes and autoimmune thyroiditis.
these molecules, Addison’s disease sets in. In the pres- membranes. Pubic and axillary hair loss is related to Treatment: Treatment requires the clearing of infec-
ence of low circulating levels of cortisol, the pituitary the lack of 17-ketosteroids, whereas hypotension is tion or treatment of the underlying cause of adrenal
responds by increasing production of adrenocorticotro- caused by the lack of aldosterone. The lack of aldoste- gland dysfunction. Supplemental hydrocortisone and
phic hormone (ACTH, corticotropin) and melanocyte- rone causes a decreased blood volume and decreased fludrocortisone are used as replacement therapy for
stimulating hormone (MSH). ACTH and MSH are serum sodium. The lack of cortisol production is respon- those with inadequate adrenal function. Hydrocorti-
derived from the same precursor protein, pro- sible for weakness, fatigue, weight loss, and decreased sone is used primarily to replace the missing cortisol,
opiomelanocortin (POMC). The pigmentary anomalies mentation. and fludrocortisone is used to replace aldosterone.

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