Congenital unilateral reticulate keratotic papules on the lower
, and Saurabh Singh,
Department of Dermatology, All India
Institute of Medical Sciences, Jodhpur,
Department of Dermatology,
All India Institute of Medical Sciences,
Dermatology Outpatient Department,
Main Outpatient Department Block,
AIIMS, Basni Phase - 2nd, Jodhpur,
Conﬂict of interest disclosures: There is no
conﬂict of interest.
What is your diagnosis?
A boy in his late teens presented with asymptomatic brown-
colored raised lesions over the right leg since birth. Lesions
gradually increased in size and number over a period of a few
years, and there were no lesions elsewhere. Family history was
noncontributory. There was no history of any preceding skin
eruption either at the time of birth or at any point thereafter.
Examination showed multiple grouped dark brown follicular
hyperkeratotic papules coalescing at the center to form plaque
over and slightly above the medial aspect of the right knee with
a few scattered follicular lesions over the adjoining thigh and
leg. Plaque showed linear and reticulate conﬁguration especially
at the borders. Majority of the lesions had a central keratotic
plug with few showing pits as remnants of fallen plugs (Fig. 1).
The rest of the mucocutaneous examination was within normal
The ﬁndings revealed marked hyperkeratosis over a prominent
follicular plug causing a cup-like depression in the center of an
essentially normal epidermis (Fig. 2a). The epidermis beneath
this plug showed cytoplasmic vacuolization with a thin rim of
cytoplasm in perinuclear location. The granular layer in this
portion had coarse keratohyalin and trichohyalin granules
(Fig. 2b). The vacuolar change spared the basal layer and
sharply corresponded to the extent of the overlying hyperker-
The patient was started on tretinoin 0.05% cream once daily
which caused visible ﬂattening of lesions after 4 weeks.
Multiple grouped dark brown follicular
hyperkeratotic papules with a central keratotic plug over the
medial aspect of the right knee
ª 2017 The International Society of Dermatology International Journal of Dermatology 2018, 57, 399–400