April 21, 2021
In 1895, after observing multiple patients, Louis Frederick Wickham reported the presence of lace-like whitish or grayish lines that were consistent in patients suffering from certain skin disorders and oral lesions. He called them Wickham's striae. Striae refers to a furrow, a stretch or wrinkle-like lines.
The Wickham's striae is most commonly associated with the oral lesion called lichen planus. This is an inflammatory condition that attacks the immune system and causes breaks, cracks and rashes on the surface of skin and the inner linings of the oral cavity. It occurs as a result of genetic predisposition, underlying medical condition (e.g. diabetes), drug reactions, hypersensitivity to dental materials, bowel diseases, food allergies, betel nut chewing, stress, tumours and infectious microbes. Some of its variants, particularly the ones in the oral cavity, hold cancerous potential. The identification of Wickham's striae in such conditions can help in early detection and diagnosis of the underlying disease.
On the skin, there are over ten conditions that are associated with Wickham's striae. Moreover, compared to the oral cavity, they are much more difficult to appreciate on the skin. Furthermore, compared to its oral association, Wickham's striae is not related with a higher cancerous potential.
Wickham's striae is associated with lichen planus irrespective of ethnicity, race and gender. In the oral cavity, Wickham's striae can be seen in the inner linings of the cheek (buccal mucosa), gingiva, lips and tongue. Investigative procedures like dermatoscopy or application of certain oils and stains can help in identification of Wickham's striae. In lichen planus, Wickham's striae are seen on the purplish papules seen in the oral cavity.
The attempt to explain the formation of Wickham's Striae has been proposed via three theories. According to the first theory, the striae are a result of one of the skin layers proliferating abnormally. Another theory suggests that a local irritation triggers or activates abnormal activity in one particular area of the mouth that leads to the formation of the lace-like lines. Finally, the third theory suggests that impaired blood supply in the affected region is likely to develop Wickham's striae.
It is still unclear at what stage of the development of lichen planus do Wickham's striae form. In his description of the papules of lichen planus, Wickham stated that the affected surface can be divided into two parts. One is a reddish component and the other is a grayish component. The reddish areas lie underneath, over which the grayish layer appears. It is from the grayish area where the lace-like lines originate. The extent of these striae vary in each case. In some cases it is restricted to the papule whereas in some more extensive cases, the whitish lines are present at the length of the buccal mucosa.
The direction of the striae is not fixed either and has been most often described as tree-like configuration. Till date, researchers have established six patterns in which Wickham's striae may present itself. These are circular, reticular (branched), radial linear, globular, perpendicular and veil-like. The presence of Wickham's striae is usually bilateral. This means that it is more often present on both sides of the mouth.
Wickham's striae disappear ones the treatment has been initiated and neared its completion. Hence, in many cases it used as a biomarker to study the severity of the disease. Treatment modalities like drug therapies and light therapies help in eliminating lichen planus. Drugs include steroids and antihistamines whereas light therapy employs ultraviolet radiations. Multivitamins help in faster healing and aggravating factors like stress can be managed by meditation and behavioural therapies.
Elimination of Wickham's striae may not necessarily mean that the underlying condition is resolved. Variants of lichen planus, namely actinic lichen planus and lichen planus pigmentosus do not see the formation of Wickham's striae. Hence, a laboratory investigation must be done to confirm the complete elimination of the condition.
The discovery of Wickham's striae has ever since helped in determining the prognosis of an existing condition. One of the earliest histological discoveries ever made, it is now tagged as a pathognomic feature of lichen planus; meaning, that it is now seen as a definitive diagnostic trait for the condition.