الفهرس 
DERMOSCOPYOnly 14 pages are availabe for public view
 |  | from | 16 |  |  |
| | | from | 16 | | |
Abstract
H
air shaft disorders are a group of congenital or acquired alterations that involve the hair shaft. Congenital disorders can be an isolated finding or can be apart of complex syndromes.Some abnormalities are associated with structural weakness of the hair shaft and therefore with hair breakage and loss.
Increased fragility and breakage is the main feature that allows classification of these disorders. Hair shaft disorders with increased fragility can be congenital as (monilithrex, pilli torti, trichorrhexis invaginata, trichothiodystrophy, trichorrhexis nodosa) or acquired as (trichorrhexis nodosa, bubble hair). Acquired disorders are more common than congenital. Hair shaft disorders without increased fragility are only congenital and include (pilli annulati, wooly hair, uncombable hair syndrome and pilli bifurcate and multigemini.
Dermoscopy, also known as epiluminescence microscopy or incident light microscopy, is a relatively new noninvasive diagnostic technique for the in vivo observation of skin lesions. Dermoscopes are modified magnifying devices that permit the visualization of pigmented structures or vessels in the epidermis and superficial dermis and generally employ x10 magnifications. Their use has gained great popularity for aiding the diagnosis of pigmented skin lesions. More recently, the use of dermoscopy has been applied for the diagnosis of non-pigmented skin lesions including skin tumours, inflammatory and infectious diseases.
Dermoscopic examination of hair and scalp is known as trichoscopy. As hair shaft disorders are rare, most studies were on their dermoscopic features are limited to case reports or series. Until a few years ago the diagnosis of hair shaft disorders was based on light microscopy or scanning electron microscopy of plucked or cut samples of hairs. The use of dermoscopy completely changed the diagnostic approach to these disorders as it is fast, noninvasive, and cost-efficient and allows for easy office diagnosis of all hair shaft abnormalities including conditions such as pili trianguli and canaliculi that are not recognizable by examining hair shafts.
Handheld dermoscopes allow for magnification of x10 to x20 and videodermatoscopes allow for magnifications up to x160. Both types of devices enable the dermatologists to distinguish fractures, irregularities, twisting, and extraneous matter without plucking or cutting hairs for microscopic examination.
In addition, dermoscopy allows for screening the entire scalp along with the eyebrows and eyelashes that may be the only affected site in some conditions most hair shaft abnormalities in fact do not affect the entire scalp but are limited to a few hairs and it can be difficult to detect the abnormality in a random sample. Dermoscopy spares the patient the inconvenience of plucking or cutting hairs for diagnostic purposes. It can, however, also be used on pulled or plucked hair samples to evaluate the phase of the roots and hair shafts.
The purpose of this study was to establish the dermoscopic criteria of the congenital hair shaft abnormalities and compare these criteria with light mircosopic finding of the same diseases.
Our study was carried out on 15 patients with congenital hair shaft abnormalities and 10 healthy subjects of the same age and sex group. These patients were digitally photographed and dermoscopicaly examined for scalp hair, eyebrows and eyelashes then followed by light microscopic examination of their scalp hair after taken some hairs by plucking.
The ability of both dermoscope and light microscope in detecting hair shaft abnormalities was nearly equal. As there were 5 cases (33.3%) showed the same features by dermoscopy and light microscopy. These are cases with monilithrix, pilli torti, trichorhexsis nodosa and pilli annulati hair.
Of interest, in the current study, we detected two cases that dermoscopy took the upper hand over light microscopy in their diagnosis,they were 2 cases of woolly hair as dermoscopy showed the crawling snake appearance of hair that was charachteristic for the disease.
But there were 4 cases that could not be diagnosed by dermoscopy and were in need to light microscope to help the diagnosis as Trichothyodystrophy, loose anagen syndrom and ectodermal dysplasia with loose anagen hair shafts. Here the dermoscope was of importance to select the hairs that should be examined by light microscope.
Finally this study confirms that dermoscopy is a fast and noninvasive new tool in the diagnosis of hair shaft abnormalities.