
Acanthosis nigricans benigna L83
Acanthosis nigricans benigna: blurred brown-black spots, in places also plaques, no subjective symptoms.

Neurofibromatosis (overview) Q85.0
type I neurofibromatosis, peripheral type or classic cutaneous form. since puberty slowly increasing, soft, 0.2-0.8 cm large, skin-coloured or slightly brownish, painless, flat or hemispherical papules and nodules in a 42-year-old patient. the bell-button phenomenon can be triggered (the papules can be pressed into the skin under pressure). café-au-lait spots up to 7 cm in diameter also appear on the trunk.

Maculopapular cutaneous mastocytosis Q82.2
Urticaria pigmentosa: about 0.5-1.0cm large, disseminated, oval or round, brownish-red spots. only when rubbed, increased reddening of the spots with accompanying itching. also during warm showers or baths increased reddening and clearly palpable elevation of the lesions. Darier phenomenon can be triggered (see neck on the right, here extensive reddening with slight itching, after rubbing this area).

Mixed connective tissue disease M35.10
Mixed connective tissue disease: deep red, blurred, poicilodermatic spots and plaques; central brown discoloration, reticular scarring.