Rosacea is a long-term skin condition that typically affects the face. It results in redness, pimples, swelling, and small and superficial dilated blood vessels. Often, the nose, cheeks, forehead, and chin are most involved. A red, enlarged nose may occur in severe disease, a condition known as rhinophyma.The cause of rosacea is unknown. Risk factors are believed to include a family history of the condition. Factors that may potentially worsen the condition include heat, exercise, sunlight, cold, spicy food, alcohol, menopause, psychological stress, or steroid cream on the face. Diagnosis is based on symptoms.While not curable, treatment usually improves symptoms. Treatment is typically with metronidazole, doxycycline,  minocycline, or tetracycline. When the eyes are affected, azithromycin eye drops may help. Other treatments with tentative benefit include brimonidine cream, ivermectin cream, and isotretinoin. Dermabrasion or laser surgery may also be used. The use of sunscreen is typically recommended.Rosacea affects between 1% and 10% of people. Those affected are most often 30 to 50 years old and female. People with paler skin or European ancestry are more frequently affected. The condition was described in The Canterbury Tales in the 1300s, and possibly as early as the 200s BC by Theocritus. Signs and symptoms
Rosacea typically begins with reddening of the skin in symmetrical patches near the center of the face. Common signs can depend on age and sex: flushing and red swollen patches are common in the young, small and visible dilated blood vessels in older individuals, and swelling of the nose is common in men.
Pathophysiology
The GNAS1 gene involved in both Pseudohypoparathyroidism type 1a and Pseudopseudohypoparathyroidism is greatly affected by imprinting. When a father who has Pseudohypoparathyroidism undergoes spermatogenesis, imprinting of the GNAS1 gene inactivates both copies of his genes: one will be Functional and the other will be defective. Tissues in the body will re-activate different copies of the GNAS1 gene selectively; the kidneys will selectively activate the (functional) maternal copy while keeping the (defective) paternally-derived gene imprinted and inactive, even in normal individuals. Since the maternally-derived GNAS1 gene is functional, renal handling of calcium and phosphate is normal, and homeostasis is maintained in Pseudopseudohypoparathyroidism. However, the rest of the tissues will instead selectively display the defective gene, resulting in haploinsufficiency of the GNAS1 product in most tissues, and giving the phenotype of Pseudohypoparathyroidism type 1a. As a result, there is also a normal response of urinary cAMP to PTH, and normal serum PTH. Diagnosis
The diagnosis is based on the presence of the Albright hereditary osteodystrophy pseudotype but without the PTH resistance. Blood tests including calcium, phosphate, and PTH will exclude other forms of Pseudohypoparathyroidism. X-rays may reveal a short fourth metacarpal. Genetic testing can confirm the diagnosis by showing GNAS gene mutation. Treatment
Treatments focuses on symptoms, with genetic counseling recommended. History
It was characterized in 1952 by Fuller Albright as "pseudo-pseudohypoparathyroidism" (with hyphen). See also
Antidisestablishmentarianism
Floccinaucinihilipilification
GNAS complex locus
Honorificabilitudinitatibus
Longest word in English
Longest words
Parathyroid hormone
Pneumonoultramicroscopicsilicovolcanoconiosis
Supercalifragilisticexpialidocious

References


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