Amyloidosis cutis dyschromica
A few reported cases have occurred in patients with other systemic conditions, but systemic amyloidosis or other disease associations have not been established.
There does not appear to be any sex predilection for the disorder, but individuals of Asian descent have been reported most commonly in the literature. Multiple members of the same family may be affected; autosomal recessive and semidominant patterns of inheritance have been described. Mutations in the GPNMB gene have been implicated in ACD.
E85.4 – Organ-limited amyloidosis
L99 – Other disorders of skin and subcutaneous tissue in diseases classified elsewhere
764849002 – Amyloidosis cutis dyschromia
Differential Diagnosis & Pitfalls
- Dyschromatosis universalis hereditaria – This can be differentiated histopathologically as amyloid deposits would not be seen.
- Epidermolysis bullosa simplex with mottled pigmentation – This condition includes blisters, which ACD typically does not. These conditions also differ in their histopathologic appearance.
- Dyskeratosis congenita – This condition also includes nail dystrophy, leukoplakia, and pancytopenia.
- Xeroderma pigmentosa – This condition also features photosensitivity and photophobia.
- Addison disease – This is accompanied by characteristic laboratory findings and differs from ACD histopathologically.
- Poikiloderma-like amyloidosis – In addition to skin findings, this condition generally includes short stature, photosensitivity, blisters, and palmoplantar hyperkeratosis.
- Dowling-Degos disease – Reticular hyperpigmentation in this condition is generally in a flexural distribution.
- Naegeli-Franceschetti-Jadassohn syndrome – Presents with reticular pigmentation, palmoplantar keratoderma, acral bullae in infancy, dental abnormalities, and hypohidrosis.
- Dermatopathia pigmentosa reticularis – This is thought to be allelic to Naegeli-Franceschetti-Jadassohn syndrome, with many similar features, but has alopecia, lack of dental anomalies, and stable reticulate hyperpigmentation.
- Weary-Kindler syndrome – Presents with congenital acral bullae, reticulate hyperpigmentation, development of acral keratoses, photosensitivity, poikiloderma, and severe periodontal disease.