๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Lichen spinulosus
Lichen spinulosus
Clinical features Lichen spinulosus is a rare dermatosis of unknown etiology which particularly affects the extensor surfaces of the extremities, back, chest, buttocks,
81 Erythrokeratoderma
A
B
Disease Inheritance Locus Gene Protein
Erythrokeratoderma variabilis (and progressive symmetrical erythrokeratoderma) AD or AR AD
1q35.1 1q35.1
GJB3 GJB4
Connexin 31 Connexin 30.3
Erythrokeratoderma variabilis with erythema gyratum repens-like lesions AD 1q35.1 GJB4 Connexin 30.3
Keratitis-ichthyosis-deafness syndrome/hystrix-like-ichthyosis deafness syndrome (KID/HID syndrome) AD 13q11-12 GJB2 Connexin 26
Oculodentodigital dysplasia AD 6q22-24 GJA1 Connexin 43
Vohwinkel keratoderma AD 13q11-12 GJB2 Connexin 26
Hidrotic ectodermal dysplasia of Clouston AD 13q11-12 GJB6 Connexin 30
face, and neck.1 Occasionally, lesions are generalized. The condition presents in the second and third decades of life as round to oval, 2โ6-cm flesh-colored and sometimes pruritic, symmetric plaques composed of multiple 1โ3-mm thorny, grouped follicular papules which protrude above the surface of the skin.1โ3 The condition is of no clinical significance. Lichen spinulosus has been described in association with atopy, Crohn disease, HIV infection, and as an adverse drug reaction.4โ7
Histologic features Lichen spinulosus is characterized by keratotic plugging of dilated follicular infundibula and a superficial perivascular and perifollicular lymphohistiocytic infiltrate.1 Sebaceous glands may be atrophic or absent. Perforating folliculitis-like features can be superimposed.
predominantly affected, but lesions may extend to involve the thighs, upper arms, and buttocks.1
Histologic features The papules consist of a cystically dilated follicular infundibulum filled with keratinous debris.4
Fig. 3.69 Keratosis pilaris atrophicans: (A) low-power view showing gross follicular hyperkeratosis and dilatation of the ostium; (B) high-power view. Note the perifollicular fibrosis extending into the reticular dermis.
Table 3.5 Diseases with connexin mutations