Sir,
A 20-year-old female presented to us with lesions over right side of her body with
mild itching and pigmentation in oral cavity since 1 month. The lesions started from
right hand which, progressed to involve lateral forearm, and arm upto the scapula.
The lesions later involved inframammary region, lower abdomen, and posterolateral
aspect of thigh on the same side followed by asymptomatic involvement of bilateral
buccal mucosa. There was no history of trauma, dental procedure, infection, drug intake
or prior dermatological diseases, such as herpes zoster. There was no family history
of identical skin disease.
On examination, multiple erythematous to hyperpigmented papules were present over
the lateral aspect of the right upper limb upto the scapular region along C7,8 (cervical)
dermatome with koebnerization [Figure 1a and b]. Multiple grouped papules of similar
morphology forming a band over right inframammary region involving T5,6 (thoracic),
right lower abdomen at T12, and right posterolateral thigh at S1 (sacral) dermatomes
was seen [Figure 2a–c]. Single hyperpigmented papule over right lower lip with hyperpigmented
patches in lacy pattern over bilateral buccal mucosa were noted [Figure 3a and b].
Nails, scalp, and genitals were normal. Systemic examination was unremarkable. Lichen
planus (LP) and lichen striatus were kept as differentials and biopsy was taken, which
showed focal mild acanthosis and hypergranulosis in the epidermis with band-like infiltrate
of lymphocytes in the upper dermis leading to disruption of the dermoepidermal junction
and pigment incontinence [Figure 4]. A mild perivascular and periappendageal lymphocytic
infiltrate with exocytosis of lymphocytes at few places was present. These features
were suggestive of LP. The patient was given topical steroids for skin lesions and
buccal mucosa. Lesions were not progressive but no improvement was seen in pigmentation
after a month of follow-up.
Figure 1
Multiple erythematous to hyperpigmented papules over (a) lateral aspect of the right
upper limb; (b) right scapular region along C7,8 distribution with koebnerization
Figure 2
Multiple erythematous to hyperpigmented papules over (a) right inframammary region
involving T5,6 dermatome, forming a band; (b) right lower abdomen at T12; (c) right
posterolateral thigh at S1 dermatomes
Figure 3
(a) Single hyperpigmented papule over right lower lip; (b) hyperpigmented patches
in lacy pattern over buccal mucosa
Figure 4
Mild acanthosis and hypergranulosis in the epidermis with band-like infiltrate of
lymphocytes in the upper dermis leading to disruption of the dermoepidermal junction
and pigment incontinence. (Hematoxylin and eosin stain, ×4 magnification)
LP is an inflammatory mucocutaneous disease in which cell-mediated immunity plays
a major role in triggering the disease. Typical cutaneous LP presents as extremely
pruritic, polygonal, flat-topped, violaceous papules, and plaques.[1] Oral mucosa
is commonly involved in LP, mostly as asymptomatic whitish and reticular patches.
Many clinical variations of LP have been described according to the configuration
and morphologic appearance, of which linear and zosteriform LP are rare. Zosteriform
pattern is a variant of LP that may occur without evidence of herpes zoster.[2] It
usually involves one or two continuous dermatomes.
Zosteriform and blaschkoid forms arise either as Koebner's phenomena, Wolf's isotopic
phenomena, or de novo from normal skin.[2] It differs from the usual LP by absence
of oral cavity involvement and severe itching,[2] which contradicts our case of unilateral
LP presenting with multiple discrete lichenoid papules along dermatomal distribution
with mild itching and oral changes with no prior history of herpes zoster or trauma
to her skin.
Distribution of lesions in linear/zosteriform LP suggest a theory of neural origin
while recently it has been suggested that most of the lesions occurring in so-called
zosteriform manner do not follow a dermatomal pattern or apparently a nerve segment
but are rather along the Blaschko's lines.[3] Some authors believe that true zosteriform
LP only exists in cases of isotopic phenomena on the sites of healed herpes zoster.[4]
Most of the cases of zosteriform LP reported as per our literature search [Table 1],
were males,[3
5
6
7
8
9
10
11
12
13
14] aged between 30 and 40 years,[5
6
7
8
9] mainly involving left side of the body,[3
5
7
9
10
11
15
16] where as our case was a 20-year-old female with involvement over right side of
the body. Only two patients had prior history of herpes zoster[12
16] and one patient had history of extracorporeal shock wave lithotripsy.[15] All
other cases did not have previous history of herpes zoster similar to our case. In
addition to lesions of LP over body our patient had mucosal involvement, which was
seen in three other cases, one with oral involvement[8] like ours and other two had
genital involvement.[6
10] Only one case had multiple non-contiguous involvement[14] as in our case, whereas
in all other cases, there was involvement of one or two dermatomes.
Table 1
Reported cases of zosteriform lichen planus
There is a definite distinction between the linear and zosteriform type of LP. In
the former, the papules appear as narrow lines about 1 or 2 cm wide, which may follow
the course of a nerve, vein, lymphatic vessel or of Voigt lines, whereas in zosteriform
a band (several centimeters wide) follows the course of a peripheral cutaneous nerve
and its branches or appears over areas of radicular nerve distribution as in our case.
The zosteriform arrangement of lichenoid papules is rare and is interpreted as a cutaneous
reaction possibly triggered by some neural factor.[17]
The histology of LP is characteristic and enables distinction from other linear dermatoses
such as lichen striatus, linear nevi, and linear psoriasis. Treatment modalities include
topical moderate- to high-potency corticosteroids, topical salicylic acid, and systemic
antihistamines. In unresponsive cases systemic corticosteroids or intralesional corticosteroids
can be instituted.
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Conflicts of interest
There are no conflicts of interest.