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ICD-9 : 277.3 • ICD-10 : E85.3
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- Amyloidosis is an extracellular deposition in various tissues of amyloid fibril proteins and of a protein called amyloid P component (AP); the identical component of AP is present in the serum and is called SAP. These amyloid deposits can affect normal body function.
- Systemic AL amyloidosis, also known as primary amyloidosis, occurs in patients with B cell or plasma cell dyscrasias and multiple myeloma in whom fragments of monoclonal immunoglobulin light chains form amyloid fibrils.
- Clinical features of AL include a combination of macroglossia and cardiac, renal, hepatic, and gastrointestinal (GI) involvement, as well as carpal tunnel syndrome and skin lesions. These occur in 30% of patients, and since they occur early in the disease, they are an important clue to the diagnosis.
- Systemic AA amyloidosis (reactive) occurs in patients after chronic inflammatory disease, in whom the fibril protein is derived from the circulating acute-phase lipoprotein known as serum amyloid A.
- There are few or no characteristic skin lesions in AA amyloidosis, which usually affects the liver, spleen, kidneys, and adrenals.
- In addition, skin manifestations may also be associated with a number of (rare) heredofamilial syndromes.
- Localized cutaneous amyloidosis is not uncommon, presents with typical cutaneous manifestations, and has no systemic involvement.
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Systemic AL Amyloidosis
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ICD-9 : 277.3 • ICD-10 : E85 
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- Rare
- Occurs in many but not all patients with multiple myeloma and B cell and plasma cell dyscrasias.
- Restrictive cardiomyopathy, renal function impairment, GI involvement with malabsorption, neuropathy.
- Prognosis poor
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Clinical Manifestation
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Smooth, waxy papules (Fig. 14-1), but also nodules on the face, especially around the eyes (Fig. 14-2) and elsewhere. Purpura following trauma, “pinch” purpura in waxy papules (Fig. 14-2) sometimes also involving large surface areas without nodular involvement. Predilection sites are around the eyes, central face, extremities, body folds, axillae, umbilicus, anogenital area. Nail changes: Similar to lichen planus (see Section 33). Macroglossia: diffusely enlarged and firm, “woody” (Fig. 14-3).
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