What is Lichen Striatus?
Lichen striatus is rare and benign skin condition that commonly affects young children. The cause of this skin condition is unknown and is characterized by the onset of pink papules in linear band. It is a self-limited skin disorder that primarily involves the arms and the legs but can also affect any part of the body.
Lichen striatus is a benign skin condition but can leave a temporary hypopigmentation or hyperpigmentation after it has resolved. The rash of lichen striatus often affects a single arm or leg only but may also exist in the neck and torso. It is a self-limiting disease that resolves on its own and is usually asymptomatic although there are some cases where mild or severe itchiness can be experienced.
Lichen striatus is prevalent among young children specifically between the ages of 5 years to 15 years and rarely affects infants and adults but the disease however, can affect people at any age. It can also affect people worldwide without racial predilection. Lichen striatus is found to be prevalent among girls approximately 3 folds compared to incidence in boys although there are some reports revealing an equal distribution of the disease in both boys and girls.
Lichen striatus occurring in adults is more aptly termed as Blaschkitis or acquired Blaschkoid dermatitis. This adult form of lichen striatus looks similar to eczema and is acquired. It is an inflammatory condition of the skin that is not present at birth.
Lichen striatus is not a life-threatening skin condition but can be disturbing due to the onset of visible rashes along the lines of Blaschko. The onset can be unappealing and it can be itchy for some although the disease is generally asymptomatic. It usually resolves without a need for treatment except in cases where the rashes are itchy and causing discomfort to the patient.
Lichen Striatus Symptoms
The hallmark of lichen striatus is the development of pink rashes in a form of a linear band where it involves the lines of Blaschko. The rashes develop as a single linear band in either arm or leg but can also develop in the neck and torso.
The lines of Blaschko are invisible lines on the skin that correspond to the pattern of developmental growth during the process of epidermal cell migration. It is different from other morphological lines of the skin as the lines of Blaschko do not correspond to the lymphatic, vascular and nervous structures of the body. It is rather a distinct line that is only made visible by several acquired or inherited diseases.
The upper spine of the body has a U-shape pattern of lines of Blaschko while the abdomen has S-shaped pattern. An inverted U-shape pattern can be found on the breast and the upper arms while the lower arms and the legs have a perpendicular pattern of lines of Blaschko.
Lichen striatus is unilateral or affects only one side of the body and solitary down the lines of Blaschko in the extremities. It can affect either of the arms and either of the legs. The development of small papules is rapid and is often asymptomatic. Pruritus is the main complaint of patients when lichen striatus becomes symptomatic. The pruritus can be mild or it can be severe in some cases. The eruption of papules usually lingers for several days to several weeks at the most.
The papules follow a linear band and may emerge in a continuous or intermittent pattern. The linear band on the other hand is composed of small lichenoid papules approximately 1 mm to 3mm in size. The colors of the papules ranges from tan, pink to skin colored while the texture may be scaly and smooth.
The linear band is about 1 cm to 2 cm wide while the length is about a few centimeters or may extend up to the full length of the extremity. In rare cases, the linear band may appear bilaterally or may be on multiple lines. In light skinned individuals, the linear band may appear as hyperpigmentation while in dark skinned individuals the linear band appears as hypopigmentation.
The nails are seldom involved in lichen striatus but is usually the only area involved and without the lesions. The involvement of the nails may occur before or after the development of linear bands in extremities or may occur along the linear band rash. The onset of lichen striatus is often limited to one nail only. Changes in nail may be seen with ridging, splitting, nail loss and pitting. The nail bed is seen with hyperkeratosis while the nail plate may have thinning or thickening or may be seen with an over curvature.
Lichen Striatus Causes
The exact cause of lichen striatus has not been established. Several predisposing factors on the other hand are being considered. Both the genetic factors and environmental stimuli are considered in the incidence of lichen striatus.
A family history of asthma and atopic dermatitis are deemed as predisposing factors in lichen striatus. This has been based on the reported cases of lichen striatus where three fourth of patients have a family history of asthma or atopic dermatitis.
The environmental stimuli such as trauma and infection are being linked to the onset of lichen striatus. The involvement of viral infection in lichen striatus is based on the elevated levels of interleukin 1-beta as revealed in the biopsy of lichen striatus specimen. The concept however has not been proven.
Pregnancy is also believed to be involved in the process of lichen striatus. It is thought to trigger the autoimmune response leading to the eruption of papules in lichen striatus.
Lichen Striatus Pictures
Pictures collection of Lichen Striatus…
Lichen Striatus Treatment
Lichen striatus is a benign skin condition that is generally harmless and non-life threatening. Treatment is not necessary and the lesion usually resolves on its own. It takes about several months before the lesions disappear. Hypopigmentation or hyperpigmentation on the other hand is common after the lesion has dissipated although only temporary.
If treatment is necessary, it is usually geared towards the relief of itchiness and dryness. Topical steroids and emollients are the usual medication for lichen striatus.
Topical steroids may help in clearing the lesion although this may take about several weeks. Emollient on the other hand is beneficial in relieving the dryness of the skin and reducing the itchiness.