DefinitionThis section has been translated automatically.
Primary cutaneous amyloidosis (keratinamyloidosis) with dense papules and very intense lesional pruritus. Recently, some authors understand itching as the primary stimulus of amyloid deposition, which is reactively followed by the described skin changes with subepidermal deposition of amyloid (due to the traumatic permanent damage caused by scratching). See also amyloidosis.
Occurrence/EpidemiologyThis section has been translated automatically.
More common among Asians and Africans. Also among Caucasians, but less frequently.
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EtiopathogenesisThis section has been translated automatically.
Principle: Apoptotic keratinocytes (this apoptotic process is a normal degradation process in the skin) convert their alpha helix into a beta leaflet structure from unexplained reasons. As a result, these keratin structures can no longer be phagocitated by macrophages. As it were, they remain in the dermis as clumsy, non-degradable ("keratinamyloid" or amyloid K) organic material. This process is not reversible.
ManifestationThis section has been translated automatically.
m:w=3:2; usually higher age.
LocalizationThis section has been translated automatically.
Extended sides of the extremities, especially lower legs (86% of cases)
rare arms (10%) and back
Clinical featuresThis section has been translated automatically.
Permanent, severe to excessive, lesional itching (itching = leading symptom)
Very hard, skin-colored to brown, usually grouped standing, warty-rough, or also lichenoid shining, 0.2-0.4 cm large, in places excoriated, nodules with tendency to confluence, so that 3.0-5.0 cm hard plaques with fielded or verrucous surface develop.
In larger studies, the symptoms of lichen amyloidosus existed 6-20 months before the initial examination.
HistologyThis section has been translated automatically.
Homogeneous eosinophilic plaques in the papilla tips, acanthosis, hyperkeratosis, hypergranulosis; lateral displacement of the reticulum cones. Traces of amyloid are often also found in the reticular dermis. The amyloid can be detected with crystal violet staining (metachromasia) or Congo red staining (green glow in polarized light). Immunohistological detection of cytokeratin positive keratin filaments (!).
Differential diagnosisThis section has been translated automatically.
External therapyThis section has been translated automatically.
- Improvement of symptoms with external glucocorticoids, e.g. 0.1% betamethasone(e.g. Betagalen, Betnesol), triamcinolone(e.g. Triamgalen, R259 ) or 0.05% clobetasol ointments or creams (e.g. Dermoxin, R054 ) under an occlusion of several hours. Clinical improvement over several days to weeks.
- In smaller foci, intralesional glucocorticoids such as triamcinolone acetonide crystal suspension(e.g. Volon A, 10-40 mg together with 3-5 ml lidocaine or mepivacaine and fan-shaped intradermal application).
- In case of extensive foci, e.g. on the back, dermabrasion or laser therapy,CO2 laser or erbium laser can be recommended. Theoretical principle: Elimination of amyloid which is not degradable by the organism by the abrasive effect with the consecutive exudative inflammatory reaction. Therapeutic effects (no itching) over months to years.
- Good effects are reported from local therapy with 50% dimethyl sulfoxide solution(DMSO) R079 (once/day for several months). Under this therapy the itching is significantly improved; regression of the lichenoid papules within 8-12 weeks.
- In single observations good effects of tacrolimus were reported.
Internal therapyThis section has been translated automatically.
- Acitretin (neotigason) initial 0.5 mg/kg bw, long-term therapy with 0.1-0.2 mg/kg bw on a trial basis as monotherapy or in combination with one of the surgical procedures (according to own experience little success).
- In severe cases with pronounced pruritus, cyclophosphamide (endoxane) 50 mg/day can be tried as long-term therapy.
Note(s)This section has been translated automatically.
LiteratureThis section has been translated automatically.
- Beier C et al (1996) Lichen amyloidosus in unusual localization. Act Dermatol 22: 67-70
- Borrowman TA et al (2003) Cutaneous nodular amyloidosis masquerading as a foot callus. J Am Acad Dermatol 49: 307-310
- Carlesimo M et al (2011) A case of lichen amyloidosus treated with acitretin. Clin Ter 162:e59-61
- Hashimoto K et al (1965) Lichen amyloidosus. J Inv Dermatol 45: 204-219
- Hung CC et al (2003) Unusual skin mainifestation of cutaneous amyloidosis. Dermatology 207: 65-67
- Özkaya-Bayazit E et al (1997) Local DMSO treatment of macular and papular amyloidosis. Dermatologist 48: 31-37
- Ruzicka T et al (1990) Cutaneous amyloidosis. Dermatologist 41: 245-255
- Salim T et al (2005) Lichen amyloidosus: a study ofclinical, histopathologic and immunofluorescence findings in 30 cases. Indian J
- Dermatol Venereol Leprol 71:166-169
- Wagner G et al (1988) Cryotherapy and etretinate (tigason)-two treatment options for lichen amyloidosus. Act Dermatol 14: 205-208
- Weyers W (1995) Lichen amyloidosus - disease entity or scratch effect. dermatologist 46: 165-172
Incoming links (15)Acitretin; Amyloidosis cutaneous nodular; Amyloidosis macular cutaneous; Amyloidosis, papular; Amyloidosis, perforating cutaneous; Clobetasol propionate cream hydrophilic 0.05% (nrf 11.76.); Colloidalmilium; Dmso solution 50% (for external therapy); Keratinamyloidoses; Keratosis verruciformis; ... Show all
Outgoing links (25)Acitretin; Amyloid; Amyloidosis (overview); Betamethasone; Clobetasol-17-propionate; Clobetasol propionate cream hydrophilic 0.05% (nrf 11.76.); Cutaneous amyloidosis (overview); Cyclophosphamide; Dermabrasion; Dimethyl sulfoxide; ... Show all
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