Background
The pigmented purpuric dermatoses are a group of chronic diseases of mostly unknown etiology that have a very distinctive clinical appearance. They are characterized by extravasation of erythrocytes in the skin with marked hemosiderin deposition.
A number of clinical patterns of pigmented purpuric dermatoses or capillaritis are recognized that may represent different presentations of the same disorder; however, this generally does not influence the treatment or the prognosis. They all show a similar histologic appearance. The term pigmented purpuric dermatoses includes Schamberg disease (ie, progressive pigmentary dermatosis), purpura annularis telangiectodes (Majocchi disease),[1] lichen aureus, itching purpura, eczematidlike purpura of Doucas and Kapetanakis, and the pigmented purpuric lichenoid dermatosis of Gougerot and Blum. Many consider itching purpura and eczematidlike purpura to be variants of Schamberg disease.
Pathophysiology
The etiology is unknown. Several cofactors have been reported that appear to influence disease presentation, including hypertension, diabetes mellitus, venous stasis, strenuous exercise, gravitational dependency, capillary fragility, focal infections, and chemical ingestion.[2] Histologically, a perivascular T-cell lymphocytic infiltrate is centered on the superficial small blood vessels of the skin, which show signs of endothelial cell swelling and narrowing of the lumen. Extravasation of red blood cells with marked hemosiderin deposition in macrophages is also found, and a rare granulomatous variant of chronic pigmented dermatosis has been reported.[3]
Early onset disease may sometimes be associated with platelet-storage defects.[4]
Etiology
The cause of pigmented purpuric dermatoses is unknown. Rare familial cases of Schamberg disease and Majocchi disease have been reported in the literature, implying a genetic cause in a minority of patients.
Epidemiology
Frequency
United States
Pigmented purpuric dermatoses are common.
International
During a 10-month period, the author's United Kingdom hospital-based dermatology practice, which serves a population of 300,000 persons, identified only 10 such cases. Five cases were diagnosed as having lichen aureus, and the remainder had more extensive capillaritis.
Race
Persons of any race can be affected by pigmented purpuric dermatoses.
Sex
Pigmented purpuric dermatoses usually occur more frequently in men than in women. However, purpura annularis telangiectodes of Majocchi is seen more frequently in women.
Age
Schamberg disease may occur in persons of any age.
Itching purpura and the dermatosis of Gougerot and Blum mainly affect middle-aged men.
Lichen aureus and Majocchi disease are predominantly diseases of children or young adults.
Prognosis
Many lesions persist or extend with time. Most eventually resolve spontaneously. Typically, the condition is asymptomatic, but pruritus may sometimes be a prominent feature in some cases, especially in patients with itching purpura or eczematidlike purpura of Doucas and Kapetanakis. These diseases have no systemic findings.
History
Patients complain about the appearance of their skin.
In Schamberg disease, irregular plaques and patches of orange-brown pigmentation develop on the lower limbs. The lesions are chronic and persist for years. With time, many of the lesions tend to extend and may become darker brown in color, but some may spontaneously clear.
In itching purpura, the lesions are much more extensive, and patients typically complain of severe pruritus.
Physical Examination
The hallmark of a pigmented purpuric dermatosis is its characteristic orange-brown, speckled, cayenne pepper–like discoloration. The lower limbs are affected in Schamberg disease, whereas itching purpura is characterized by more generalized skin involvement.
In lichen aureus, the eruption is usually a solitary lesion or a localized group of golden brown lesions that may affect any part of the body; however, the leg is the most commonly affected area. Linear or segmental forms of lichen aureus have been reported.
Majocchi disease is characterized by small annular plaques of purpura that contain prominent telangiectasias.
Pigmented purpura with lichenoid-type skin change is yet another clinical variant, which Gougerot and Blum first reported. Lesions appear similar to those of Schamberg disease in association with red-brown lichenoid papules.
Note the clinical images below.
View Image | Pigmented purpuric dermatitis affecting the trunk. Some of the lesions show the characteristic orange-brown, speckled, cayenne pepper–like discolorati.... |
View Image | Lichen aureus is the name given to localized pigmented purpuric dermatitis or capillaritis. In this patient, the skin on the extensor surface of the e.... |
View Image | Capillaritis affecting the lower legs is known as Schamberg disease. In Schamberg disease, irregular plaques and patches of orange-brown pigmentation .... |
Laboratory Studies
A complete blood cell count is necessary to exclude thrombocytopenia, and coagulation screening helps to exclude other possible causes of purpura.
Imaging Studies
Dermoscopy has been reported to be a useful tool for assisting the clinical diagnosis of pigmented purpuric dermatoses.[16, 17]
Other Tests
Capillary fragility may be assessed by the Hess test.
Procedures
A skin biopsy helps to confirm the diagnosis of a pigmented purpuric eruption and aids in excluding cutaneous T-cell lymphoma, which in its early stages may closely mimic a pigmented purpuric dermatitis both clinically and histologically.[18]
Histologic Findings
Histologically, a perivascular infiltrate of lymphocytes and macrophages is centered on the superficial small blood vessels of the skin. Signs of endothelial cell swelling and narrowing of lumina may be seen, as demonstrated in the image below.
View Image | Endothelial cell swelling is a histologic feature of capillaritis. This biopsy sample was obtained from a patient with lichen aureus. |
The infiltrate is composed of predominantly CD4+ lymphocytes along with occasional CD1a+ dendritic cells. Plasma cells and neutrophils are occasionally present; the latter is not uncommon in lesions of itching purpura. Extravasation of red blood cells with marked hemosiderin deposition in macrophages is typically seen, as demonstrated in the image below. However, the degree of hemosiderin deposition may be variable, and it can be minimal in early lesions of itching purpura.[19]
View Image | Hemosiderin deposition is seen in dermal macrophages in this biopsy sample obtained from a patient with lichen aureus. |
Histochemical staining with Perls stain and Fontana-Masson stain, to demonstrate iron (hemosiderin) and exclude melanin pigment respectively, may be helpful. Hemosiderin deposition in the dermis is more superficial in pigmented purpuric dermatitis than that seen in stasis dermatitis, which is a useful differentiating feature. Mild epidermal spongiosis and exocytosis of lymphocytes may be seen in all variants except lichen aureus, which, in general, tends to show a bandlike infiltrate separated from the epidermis by a thin rim of uninvolved collagen.
Kerns et al described an unusual variant of pigmented purpuric dermatoses, granulomatous pigmented purpura, in a 42-year-old white woman, and Wong et al reported 2 cases of a similar variant.[20, 21]
Medical Care
No medical intervention is of consistent benefit for the treatment of the pigmented purpuric dermatoses.
Pruritus may be alleviated by the use of topical corticosteroids and antihistamines.
Associated venous stasis should be treated by compression hosiery.
Prolonged leg dependency should be avoided.
The use of narrowband UVB and psoralen plus UVA have shown to be effective treatments for some patients with pigmented purpuric dermatoses.[22, 23, 24, 25, 26]
Tamaki et al reported successful treatment of pigmented purpuric dermatoses using griseofulvin.[27] Treatment with oral cyclosporin has also been successful.[28]
Successful therapy with ascorbic acid (500 mg twice daily) and rutoside (50 mg twice daily) has also been reported.[29] Anecdotal data exist for calcineurin-inhibitors, colchicine, pentoxifylline, immunosuppressants, ultraviolet therapy, and laser therapy.[30]
Long-Term Monitoring
A follow-up consultation is required for cases in which initially diagnostic uncertainty exists, particularly to exclude cutaneous lymphoma.
Topical steroid treatment if used long term should be monitored for the possible development of adverse effects.
Medication Summary
The goals of pharmacotherapy are to reduce morbidity and to prevent complications.
Hydrocortisone topical (Westcort)
Clinical Context:
Hydrocortisone topical is an adrenocorticosteroid derivative suitable for application to skin or external mucous membranes. It has mineralocorticoid and glucocorticoid effects, resulting in relief of pruritus.
Clobetasol (Temovate)
Clinical Context:
Clobetasol is a class I superpotent topical steroid; it suppresses mitosis and increases the synthesis of proteins that decrease inflammation and cause vasoconstriction.
Betamethasone topical (Diprolene, Betatrex)
Clinical Context:
Betamethasone topical is for inflammatory dermatoses responsive to steroids. It decreases inflammation by suppressing the migration of polymorphonuclear leukocytes and reversing capillary permeability.
Class Summary
These agents are effective in relieving pruritus. These agents have anti-inflammatory properties and cause profound and varied metabolic effects. They modify the body's immune response to diverse stimuli.
Diphenhydramine (Benadryl, Benylin, Diphen, AllerMax)
Clinical Context:
Diphenhydramine is for symptomatic relief of pruritus caused by the release of histamine in inflammatory reactions.
Class Summary
These agents may treat itching by blocking effects of endogenously released histamine.
Author
Darius Mehregan, MD, Associate Professor, Hermann Pinkus Chairman of Dermatology, Department of Dermatology, Wayne State University School of Medicine; Clinical Associate Professor of Pathology, University of Toledo College of Medicine; Dermatopathologist, Pinkus Dermatopathology Laboratory; Consulting Staff, Department of Dermatology, J Dingell Veterans Affairs Medical Center
Disclosure: Nothing to disclose.
Coauthor(s)
Jennifer Michelle Heyl, MD, Resident Physician, Department of Dermatology, Wayne State University School of Medicine
Disclosure: Nothing to disclose.
Rahil M Dharia, Wayne State University School of Medicine
Disclosure: Nothing to disclose.
Specialty Editors
Richard P Vinson, MD, Assistant Clinical Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine; Consulting Staff, Mountain View Dermatology, PA
Disclosure: Nothing to disclose.
Lester F Libow, MD, Dermatopathologist, South Texas Dermatopathology Laboratory
Disclosure: Nothing to disclose.
Chief Editor
Dirk M Elston, MD, Professor and Chairman, Department of Dermatology and Dermatologic Surgery, Medical University of South Carolina College of Medicine
Disclosure: Nothing to disclose.
Additional Contributors
Jean-Hilaire Saurat, MD, Chair, Professor, Department of Dermatology, University of Geneva, Switzerland
Disclosure: Nothing to disclose.
Acknowledgements
The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous authors, John D Wilkinson, MD, MBBS, MRCS, FRCP, and Cedric C Banfield, BSc, MSc, MBBS, MRCP(UK), to the development and writing of this article.
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