ContentsSynopsisCodesLook ForDiagnostic PearlsDifferential Diagnosis & PitfallsBest TestsManagement PearlsTherapyReferencesView all Images (48)
Lichen amyloidosis
Print Captions OFF
Other Resources UpToDate PubMed

Lichen amyloidosis

Print Images (48)
Contributors: Jeffrey M. Cohen MD, Laurie Good MD, Whitney A. High MD, JD, MEng, Susan Burgin MD
Other Resources UpToDate PubMed

Synopsis

Lichen amyloidosis (LA) is the most common of 4 forms of primary cutaneous amyloidosis (lichen, macular, and nodular amyloidosis, and the exceedingly rare entity of amyloidosis cutis dyschromica). In LA, a proteinaceous material, amyloid, which is derived from keratinocytes, is deposited in the superficial dermis without involvement of other tissue.

While the cause of LA is incompletely understood, it is associated with, and probably caused by, friction and scratching with fingernails or implements such as towels or brushes.

Clinically, LA manifests as hyperpigmented papules that coalesce to form thick plaques with a "seafloor-like" rippled appearance. The most common location is the pretibial area, but the thighs, forearms, and back can also be involved. LA and macular amyloidosis (MA) are believed to exist on a spectrum and are mainly differentiated by the nature of the primary lesion (papules and plaques in LA and macules and patches in MA) and histopathologic findings. Some patients also display features of both LA and MA, which is termed "biphasic amyloidosis."

LA is intensely pruritic. LA has been reported in association with a few syndromes, particularly multiple endocrine neoplasia type 2A (Sipple syndrome). LA in this syndrome is usually localized to the back in the intrascapular area, and it is histologically and biochemically identical to other forms of keratinocyte-derived LA unassociated with syndromic disease.

Codes

ICD10CM:
E85.4 – Organ-limited amyloidosis

SNOMEDCT:
718105008 – Lichen amyloidosis

Look For

Subscription Required

Diagnostic Pearls

Subscription Required

Differential Diagnosis & Pitfalls

  • Notalgia paresthetica (NP) – This condition is identified by a persistent itching sensation of the upper back, usually over one or both scapulae or in the interscapular area. Most cases of NP, even in otherwise healthy individuals, are thought to have a neurogenic origin. There are usually no primary skin lesions, but changes secondary to persistent rubbing and scratching may lead to hyperpigmentation, excoriation, lichenification, and MA. NP scratching leads to cutaneous deposition of keratin-derived amyloid in some chronic cases. Itch caused by NP may be the underlying trigger for the rubbing and scratching associated with LA.
  • Lichen simplex chronicus (LSC) – A form of neurodermatitis in which intensely pruritic plaques develop as a consequence of chronic manipulation; it is less likely to have the seafloor-like appearance and will not show superficial amyloid deposition on biopsy.
  • Hypertrophic lichen planus (LP) – This form of LP very often affects the pretibial surface but may also affect the skin and mucosa elsewhere and does not show superficial amyloid deposition on biopsy.
  • Papular mucinosis – This condition usually affects multiple areas beyond the pretibial surface and is often associated with an immunoglobulin G (IgG) paraproteinemia that is not present in LA.
  • Pretibial myxedema – Associated with thyroid disease.

Best Tests

Subscription Required

Management Pearls

Subscription Required

Therapy

Subscription Required

References

Subscription Required

Last Reviewed: 01/06/2020
Last Updated: 01/06/2020
Copyright © 2020 VisualDx®. All rights reserved.
Lichen amyloidosis
Captions OFF Print 48 Images Filter Images
View all Images (48)
(with subscription)
 Reset
Lichen amyloidosis : Chest, Extensor distribution, Leg, Upper back, Smooth papules, Smooth plaques, Arms
Clinical image of Lichen amyloidosis
A close-up of grouped, monomorphic, reddish, and violaceous papules forming a plaque.
Copyright © 2020 VisualDx®. All rights reserved.