Keratosis follicularis spinulosa decalvans (KFSD) is a rare, inherited, skin disorder that affects men predominately and is characterized by hardening of the skin (keratosis) in several parts of the body. Most frequently, the face, neck, and forearms are involved. The thickening of the skin is accompanied by the loss of eyebrows, eyelashes and beard. Baldness (alopecia) usually occurs.
Keratosis follicularis spinulosa decalvans is one form of the ichthyoses, a group of inherited disorders of the skin in which the skin tends to be thick and rough, and to have a scaly appearance. Hardening of the skin around the hair follicles leads to scarring and baldness. Allergic reactions (atopy), reduced tolerance of bright light (photophobia), and inflammation of the eye’s cornea (keratitis) may also occur. Occasionally, the teeth become stained.
The word decalvans comes from the Greek for snake and alludes to the whorls and winding streaks characteristic of the pattern of baldness in this disorder. The name is often accompanied by the phrase “cum ophiasi” which simply means baldness.
Keratosis follicularis spinulosa decalvans is inherited as an X-linked dominant trait.
Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome and females have two X chromosomes. Each chromosome has a short arm designated “p” and a long arm designated “q”. Chromosomes are further subdivided into many bands that are numbered. For example, “chromosome Xp22.2-p22.13” refers to a region between bands 22.2 and 22.13 on the short arm of the X chromo-some. The numbered bands specify the location of the thousands of genes that are present on each chromosome.
Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother.
X-linked dominant disorders are caused by an abnormal gene on the X chromosome, but in these rare conditions, females with an abnormal gene are affected with the disease. Males with an abnormal gene are more severely affected than females, and many of these males do not survive.
Keratosis Follicularis Spinulosa Decalvans is a rare disorder affecting males more severely than females.
In most instances the appearance of the skin determines the diagnosis but a family history and physical examination are often required to rule out other possible causes of scaly, dry skin.
Some physicians may examine skin tissue under a light microscope or even under an electron microscope.
The dry scaly skin of KFSD is treated by applying skin softening (emollient) ointments, preferably plain petroleum jelly. This can be especially effective after bathing while the skin is still moist. Salicylic acid gel is another particularly effective ointment. The skin should be covered at night with an airtight, waterproof dressing when this ointment is used. Lactate lotion can also be an effective treatment for this disorder.
Drugs derived from Vitamin A (retinoids) such as tretinoin, motretinide, and etretinate are often effective against symptoms of Ichthyosis, but can cause toxic effects on the bones in some cases. A synthetic derivative of Vitamin A, isotretinoin, when taken by pregnant women, can cause severe birth defects to the fetus. These Vitamin A compounds have not yet been approved by the Food and Drug Administration (FDA) for treatment of Ichthyosis, and should be avoided by women of child-bearing age.
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