Lichen planus pigmentosus L43.8

Pock, 2001

Rare, brownish-colored variant of classic lichen planus, usually localized in the large bends of the joints, in which the characteristic red-violet color of lichen planus is overlaid or completely replaced by a brown color (pigment incontinence). agert

Has been described preferentially in Caucasians and Asians.

Worldwide, about 50 cases have been described so far (note: such numbers, however, say little about the actual prevalence of lichen planus pigmentosus inversus).

Affected are adults between 40 and 60 years of age. In children this clinical picture has not been described. w>m=2:1

Lichen planus pigmentosus inversus occurs mainly in the intertriginous areas, such as the axillae, popliteal fossae, submammary region, groin, vulva and penis.

Well-demarcated, disseminated, 0.2-0.5 cm, only slightly pruritic, purplish-brown or homogeneous brown patches are found. These may confluence to form extensive, irregularly configured, patches (see Fig.). The lesions tend to be chronic, lasting months or years.

The histology of this variant of lichen planus shows the characteristic phenomena of lichen planus, with a band-shaped, lichenoid infiltrate, usually only slight orthohyperkeratosis (intertrigines) and a conspicuously strong pigment incontinence.

• Fixed toxic drug exanthema
• acanthosis nigricans
• Candidaintertrigo
• Erythrasma
• Ashy dermatosis

1. Chen S et al (2015) Lichen planus pigmentosus-inversus: report of three Chinese cases and review of the published work. J Dermatol 42: 77-80
2. Ghorbel HH et al (2014) Lichen planus pigmentosus inversus. Indian J Dermatol Venereol Leprol 80:580
3. Murzaku EC et al (2014) Axillary lichen planus pigmentosus-inversus: dermoscopic clues of a rare entity. Diagnosis: lichen planus pigmentosus (LPP). J Am Acad Dermatol 71:e119-20
4. Pock L et al (2001) Lichen planus pigmentosus inversus. J Eur Acad Dermatol Venereol 15: 452-454
5. Schmid C et al (2018) Slate grey patches in both armpits. Dermatologist 69: 177-179
6. Sindhura KB (2015) Lichen planus pigmentosus: a retrospective clinico-epidemiological study with emphasis on the rare follicular variant. J Eur Acad Dermatol Venereol doi: 10.1111/jdv.1345