ARTICLE
Auteur(s) : Yasuhiro Kawachi, Shijima
Taguchi, Yasuhiro Fujisawa, Junichi Furuta, Yasuhiro Nakamura,
Yoshiyuki Ishii, Fujio Otsuka
Department of Dermatology, Institute of Clinical
Medicine, University of Tsukuba, 1-1-1, Tennodai, Tsukuba,
Ibaraki 305-8575, Japan
accepté le 3 Mars 2009
Patients with systemic monogenic hereditary skin diseases
sometimes develop segmental cutaneous manifestations of underlying
systemic skin disease. Two different types of segmental
manifestation are seen in autosomal dominant skin diseases: type 1
reflects heterozygosity of a de novo postzygotic mutation occurring
at an early stage of embryogenesis, while type 2 reflects
postzygotic mutation at an early developmental stage and results in
loss of heterozygosity (LOH) in heterozygous embryos that later
develop skin lesions with a non-segmental, diffuse distribution
[1]. On the other hand, Happle recently proposed a “superimposed”
segmental manifestation, applicable to segmental cutaneous lesions
arising within a background of systemic polygenic skin disorders,
because discrimination between type 1 and type 2 segmental
manifestations is impossible in polygenic disorders [2]. According
to this concept, LOH occurring in one of the important genes
involved in predisposition to the underlying systemic disease may
be considered the pathogenesis of the segmental linear lesions.
Previous case reports describing segmental psoriasis, lichen
planus, lupus erythematosis, atopic dermatitis, pemphigus,
vitiligo, graft-versus-host disease, granuloma annulare, erythema
multiforme, and drug eruption occurring in cases of the same
systemic diseases have been re-evaluated with reference to the
concept of superimposition [2].
Here, we report a case of superimposed segmental dermatitis that
persisted for at least 6 years without complete remission, and was
accompanied by preceding chronic prurigo on the extremities. This
is the first report of superimposed segmental manifestation within
a background of systemic chronic prurigo.
Case report
A 75-year-old man with a 20-year history of chronic prurigo mainly
on both arms, presented with a 3-year history of unilateral
pruritic linear eruptions on the left leg. Physical examination
revealed discrete and grouped erythematous papules and plaques on
the flexor side of the left leg, which became flattened on the
buttock. The eruptions were arranged in a linear shape
corresponding to Blaschko’s lines (figure 1A) and the
eruptions on the thigh were apparently eczematous papulovesicles
with exudative crusts (figure 1B). The most
distal eruptions on the leg became erosive and exudative due to the
patient’s scratching (figure 1C). There were
also typical pruriginous and eczematous lesions with itching on
both arms (figure
1D) and the trunk. A skin biopsy taken from the
linear-shaped eruption on the left leg revealed subacute spongiotic
dermatitis with hyperkeratosis, acanthosis, exocytosis of lymphoid
cells, intercellular edema, spongiosis of epidermis, and a fairly
dense lymphohistiocytic infiltrate in the papillary and upper
dermis (figures 2A and
B). The patient showed no histopathological findings
indicative of a lichenoid reaction, such as liquefaction
degeneration of the epidermis, Civatte bodies, or band-like
infiltration of lymphoid cells beneath the epidermis.
Immunohistochemical examination demonstrated that the majority of
infiltrating lymphocytes in the epidermis and the upper dermis were
CD4-positive cells (figures 2C and D), and
numerous CD1a-positive Langerhans cells were detected in the
epidermis (figure
2E). A subsequent biopsy from a prurigo lesion on the
dorsal aspect of the right forearm indicated more chronic
dermatitis with hyperkeratosis, parakeratosis, acanthosis, and less
spongiosis in the epidermis (data not shown). Topical treatment
with 0.05% betamethasone butyrate propionate ointment partially
improved the linear eruption. However, during the 3-year
observation period, the linear eruption did not disappear
completely and was exacerbated after cessation of therapy.
Discussion
Several acquired inflammatory linear dermatoses, including linear
lichen planus, lichen striatus, Ulinear psoriasis, CHILD
(congenital hemidysplasia with ichthyosiform erythroderma and limb
defects) nevus, and ILVEN (inflammatory linear verrucous epidermal
nevus), could be considered in differential diagnosis in the
present case. In rare cases, lichen planus may be arranged
linearly. However, lichen planus is characterized histologically by
a subepidermal inflammatory infiltrate associated with damage to
the epidermal basal layer and lack of epidermal spongiosis. Lichen
striatus usually occurs during childhood and is not dominated by
spongiosis and the infiltrate lacks eosinophils. Moreover,
immunohistological examination was performed to determine the
T-cell subset (CD4 and CD8) and CD1a-positive cells in the
epidermal infiltrate. Lichen planus and lichen striatus frequently
show epidermal infiltrate, consisting mainly of CD8-positive T
cells [3-5] and decreased CD1a-positive cells [5, 6], which were
not noted in the present case. The CD4-dominant epidermal
infiltrate and the increased number of CD1a-positive Langerhans
cells observed in this case reflected the eczematous nature of the
pathogenesis of this disease. Psoriasis rarely shows obvious
spongiosis, which was noted in our case. CHILD nevus and ILVEN are
usually present at birth or arise in childhood and are recalcitrant
to topical steroid treatment.
The Blaschko lines are currently thought to reflect cell
migration and clonal expansion of embryonic skin tissue during
embryogenesis [7] and the association of Blaschko lines with
genetic mosaicism has led to the hypothesis that the pattern
represents genetically abnormal skin contrasting with genetically
normal skin [8]. The genetic mosaicism that appears along Blaschko
lines is considered to result from somatic postzygotic mosaicism.
Authentic genetic mosaicism has been confirmed in X-linked
diseases, such as incontinentia pigmenti [9]. However, there is
little evidence regarding how the clonal hypothesis of Blaschko
lines is related to the pathogenesis of acquired inflammatory
diseases along the lines of Blaschko. Karyotype analysis carried
out in a patient with Blaschko dermatitis showed various
abnormalities involving chromosome 18 in lesional skin but not in
abnormal-appearing skin [10], while the molecular mechanism through
which the genetic mosaicism can lead to linear cutaneous
inflammation along the lines of Blaschko remains unclear. However,
the segmental manifestation of eczema along Blaschko’s lines
indicates a crucial role of lesional skin cells, such as
keratinocytes, fibroblasts, or vascular endothelial cells, as well
as immune cells, in the pathogenesis of this disease.The
designation “acquired Blaschko dermatitis” has been applied to
acquired unilateral eczematous linear lesions arranged along the
lines of Blaschko. This condition was first described by Grosshans
and Marot in 1990 [11] as “Blaschkite de l’adulte”, and a second
case of this disease entity was reported subsequently by Megahed
et al. as “acquired relapsing self-healing Blaschko
dermatitis” emphasizing the recurrent nature of the disease [12].
Only a few cases have since been reported [10, 13-15]. These cases
differ significantly from the present case with regard to the
absence of an underlying systemic eczematous condition. The
coexistence of the segmental eczematous lesion with systemic
chronic prurigo in the present case indicates the increased
susceptibility of the lesional skin to eczema based on the
underlying systemic eczematous immune condition. Happle recently
proposed the designation “superimposed” segmental manifestation
applicable to segmental cutaneous lesions arising within a
background of systemic polygenic skin disorders. According to this
concept, the case presented here is an example of superimposed
segmental manifestation along Blaschko lines of a systemic
eczematous condition due to chronic prurigo. The persistent course
in the present case may have been due to the underlying systemic
eczematous condition, which augments the activity of the lesional
eczema. As examples of superimposed segmental manifestation of
systemic eczematous conditions, two cases of linear-shaped
dermatitis arising within a background of atopic dermatitis have
previously been reported [16, 17].
Acknowledgments
Conflict of interest : none. Financial support : none.
References
1 Poblete-Gutierrez P, Wiederholt T, Konig A,
Jugert FK, Marquardt Y, Rubben A, Merk HF,
Happle R, Frank J. Allelic loss underlies type 2
segmental Hailey-Hailey disease, providing molecular confirmation
of a novel genetic concept. J Clin Invest 2004; 114: 1467-74.
2 Happle R. Superimposed segmental manifestation of
polygenic skin disorders. J Am Acad Dermatol 2007; 57: 690-9.
3 Ammar M, Mokni M, Boubaker S, El Gaied A,
Ben Osman A, Louzir H. Involvement of granzyme B and
granulysin in the cytotoxic response in lichen planus. J Cutan
Pathol 2008; 35: 630-4.
4 Wenzel J, Scheler M, Proelss J, Bieber T,
Tuting T. Type I interferon-associated cytotoxic inflammation
in lichen planus. J Cutan Pathol 2006; 33: 672-8.
5 Zhang Y, McNutt NS. Lichen striatus. Histological,
immunohistochemical, and ultrastructural study of 37 cases. J Cutan
Pathol 2001; 28: 65-71.
6 Gianotti R, Restano L, Grimalt R, Berti E,
Alessi E, Caputo R. Lichen striatus--a chameleon: an
histopathological and immunohistological study of forty-one cases.
J Cutan Pathol 1995; 22: 18-22.
7 Moss C. Cytogenetic and molecular evidence for cutaneous
mosaicism: the ectodermal origin of Blaschko lines. Am J Med Genet
1999; 85: 330-3.
8 Konig A, Horster S, Vakilzadeh F,
Happle R. Type 2 segmental manifestation of Hailey-Hailey
disease: poor therapeutic response to dermabrasion is due to severe
involvement of adnexal structures. Eur J Dermatol 2000; 10:
265-8.
9 Happle R. Lyonization and the lines of Blaschko. Hum
Genet 1985; 70: 200-6.
10 Lipsker D, Cribier B, Girard-Lemaire F,
Flori E, Grosshans E. Genetic mosaicism in an acquired
inflammatory dermatosis following the lines of Blaschko. Arch
Dermatol 2000; 136: 805-7.
11 Grosshans E, Marot L. Ann Dermatol Venereol 1990;
117: 9-15; [Blaschkitis in adults].
12 Megahed M, Reinauer S,
Scharffetter-Kochanek K, Milde P, Holzle E,
Goerz G, Ruzicka T. Acquired relapsing self-healing
Blaschko dermatitis. J Am Acad Dermatol 1994; 31: 849-52.
13 Betti R, Vergani R, Gualandri L,
Crosti C. Acquired self-healing Blaschko dermatitis in an
adult. Australas J Dermatol 1998; 39: 271-2.
14 Lee HJ, Kang WH, Hann SK. Acquired Blaschko
dermatitis: acquired relapsing self-healing Blaschko dermatitis. J
Dermatol 1996; 23: 639-42.
15 Mercy P, Ghorpade A, Das MN, Soud A,
Puttoo S, Sharma D, Jain A. Acquired Blaschkoid
dermatitis. Indian J Dermatol Venereol Leprol 2007; 73: 415-6.
16 Hladik F, Jurecka W, Hayek B, Stingl G,
Volc-Platzer B. Atopic dermatitis with increased severity
along a line of Blaschko. J Am Acad Dermatol 2005; 53:
S221-S224.
17 Taieb A. Linear atopic dermatitis (’naevus atopicus’): a
pathogenetic clue? Br J Dermatol 1994; 131: 134-5.
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