Derm Dx: Itchy, Hyperpigmented Rash on the Upper Back - Dermatology Advisor

Derm Dx: Itchy, Hyperpigmented Rash on the Upper Back

Slideshow

  • macular amyloidosis 34yo Hisp female

A 34-year-old Hispanic woman presents for evaluation of an itchy rash on her upper back, which was first noted approximately 3 years prior and is progressing in severity. Her medical history is significant for hypothyroidism and borderline diabetes. Past therapies have included topical ketoconazole shampoo and betamethasone cream, both of which proved ineffective. Examination reveals a variegate pattern of hyperpigmentation.

 

Slideshow by Julie Grandinetti, PA-C and Dr. Stephen Schleicher, MD.

Macular amyloidosis, also referred to as intrascapular amyloidosis, is a chronic pigmentary disorder of the skin and is one of the 3 most common variants of primary localized cutaneous amyloidosis.1,2 Cutaneous amyloidosis is characterized by deposition of amyloid in the...

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Macular amyloidosis, also referred to as intrascapular amyloidosis, is a chronic pigmentary disorder of the skin and is one of the 3 most common variants of primary localized cutaneous amyloidosis.1,2 Cutaneous amyloidosis is characterized by deposition of amyloid in the skin without involvement of internal organs. Macular amyloidosis lesions are seen characteristically in the scapular region, with less potential to appear on the thighs, shins, arms, breasts, or buttocks.3 Clinically, macular amyloidosis are 2- to 3-mm moderately pruritic and hyperpigmented lesions that appear on the upper back region.3 Pigmentation of the lesions is typically not uniform and they have a characteristic “salt and pepper” or rippled appearance on physical examination.4 Most cases of macular amyloidosis have been reported from Asia and Central America, predominantly affecting women between the ages of 40 to 70 years old.1 The disorder has also been associated with multiple endocrine neoplasia syndromes.

Adequate control is often difficult to achieve. Friction and chronic rubbing should be avoided. Potent topical corticosteroids under occlusion or in combination with keratolytic agents may be effective along with ultraviolet light therapy.4 Case reports document improvement after treatment with ablative lasers.5

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References

1. Braun-Falco O, Plewig G, Wolff HH, Burgdorg WHC. Dermatology. Berlin: Springer-Verlag; 2000:1281-1282.

2. Bolognia J, Jorizzo J, Schaffer J. Dermatology: Third Edition Volume One. China:Elsevier; 2012:702-703.

3. Rongiolette F, Smoller B, eds. Clinical and Pathological Aspects of Skin Diseases in Endocrine, Metabolic, Nutritional and Deposition Disease. London: Springer; 2010:133-136. 

4. James W, Berger T, Elston D, Neuhaus I. Andrews’ Diseases of the Skin: Clinical Dermatology (12th ed). Philadelphia: Elsevier; 2011:509-512.

5. Korbi M, Akkari H, Soua Y, et al. Lichen amyloidosis successfully treated with fractional ablative laser CO2: a new alternative therapeutic. J Cosmet Laser Ther. 2018;1-3.

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