Colloid milium are benign skin lesions that may be confused with cutaneous amyloidosis. The clinical findings are important for making the diagnosis.

Clinical phenotypes:

(1) juvenile

(2) adult

(3) nodular


Risk factors for adult colloid milium:

(1) sun exposure

(2) chemical exposures (fertilizers, petroleum)

(3) drugs (hydroquinone)


Clinical features of adult colloid milium:

(1) lesions on sun-damaged skin, especially the face

(2) lesions are non-pruritic

(3) purpura are absent


A skin biopsy shows:

(1) small nodules of eosinophilic colloid material in the papillary dermis

(2) adjacent solar elastosis

(3) Grenz zone between lesion and epidermis

(4) Congo red, thioflavin T and immunostains for amyloid-P are often postive


Differential diagnosis:

(1) cutaneous amyloidosis

(2) nodular colloid degeneration

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