Progressive Macular Hypomelanosis L81.6

Guillet et al. 1988

Chronic, disseminated, nummular and confluent hypomelanosis of the trunk and, more rarely, of the lower extremities with nummular, non-scaling bright spots, often confluent in the midline of the body. Persons with a darker complexion are more frequently affected.

Propionibacterium acnes (subtype III was proven to be present in 73.9% of patients compared to a healthy control population with 14.2%) seems to play an essential role etiopathogenetically(Petersen RL et al. 2017) by producing a factor X that interferes with melanogenesis and leads to a reduced melanin production with altered melanogenesis (see Pityriasis versicolor).

Preferably between the ages of 10 and 50.

Preferred on the fuselage

Disseminated, 2.0-5.0 cm, indistinctly circumscribed (differentiation from vitiligo), non-scaling, white or grayish-white, round, oval or circular patches. No itching. Wood's light can show accentuation of the patches with faint red fluorescence around the macules and more obvious red fluorescence of the follicles (this finding is not always found).

Decreased pigmentation of the otherwise completely normal epidermis and dermis. Melanocyte number decreased. Ultrastructurally, there is an increased number of immature melanosomes.

Pityriasis versicolor alba (native mycological preparation)

Disseminated Lichen sclerosus (histological differentiation possible)

Confetti type of morphea (histological differentiation possible)

Vitiligo (the white spotting of Vitiligo is more prominent and sharply defined)

UVB irradiations with UVB-narrowband. Alternatively, combination therapy with 5% benzoyl peroxide (+ PUVA).

PMH has been observed in Central Europe in recent years, particularly in dark-skinned female migrants from tropical countries.

1. Böhm M (2015) Differential diagnosis of hypomelanosis. Dermatologist 66: 945-958
2. Fistarol S et al (2010) Pigmentary disorders. JDDG 8: 187-203
3. Leonard N et al (2020) Successful treatment of progressive macular hypomelanosis. Dermatol Reports 12: 8509.
4. Montero LC et al (2011) Progressive macular hypomelanosis, excellent response with narrow-band ultraviolet B phototherapy. Photodermatol Photoimmunol Photomed 27:162-163.
5. Petersen RL et al (2017) Propionibacterium Acnes Phylogenetic Type III is Associated with Progressive Macular Hypomelanosis. Eur J Microbiol Immunol (Bp) 7:37-45.