מחלת שמברג

What is Schamberg's disease?

Synonyms: progressive pigmented purpuric dermatitis, Gougerot-Blum capillaritis, itching purpura, pigmented purpuric eruption¹

Schamberg's disease is the most common type of the pigmented purpuric dermatoses (PPDs). It is chronic, benign, cutaneous eruptions characterised by petechiae, purpura and increased skin pigmentation (brown, red, or yellow patchy). The PPDs are grouped into:

• Progressive pigmentary purpura or Schamberg's disease.

• Pigmented purpuric lichenoid dermatitis of Gougerot and Blum - red/brown papules and plaques in men - which responds to psoralen combined with ultraviolet A (PUVA) treatment.

• Purpura annularis telangiectodes - rare, with a preponderance in young females and manifesting as annular erythematous plaques and patches.

• Eczematoid-like purpura of Doucas and Kapetanakis - occurring in men, with bilateral intensely itchy lesions on legs.

• Lichen aureus - a localised persistent form of pigmented purpuric dermatitis.

• Itching purpura of Lowenthal (disseminated pruriginous angiodermatitis) - rare (like Schamberg's disease) but accompanied by itching.

There is clinical and histological overlap between these and they may actually represent variable presentations of the same disease process.

Who is affected by Schamberg disease? (Epidemiology)

Schamberg's disease is rare and there are few epidemiological studies in the literature.

Schamberg disease may affect all ages but commonly occurs in middle-aged to older men and less frequently in children, although cases have been reported in children aged under two. ²

There has been a case report of four family members with Schamberg's disease, suggesting a possible genetic link.³

Schamberg's disease causes (aetiology) ⁴

The underlying cause is not known. However, the following have been postulated:

• Recent viral infection.

• צריכת אלכוהול.

• Hypersensitivity to an unknown causal agent.

• Aberrant cell-mediated immunity (perivascular infiltrate has specific types of CD cells only).

• Associated with certain medications - thiamine, aspirin, chlordiazepoxide and paracetamol. It has also been reported with bezafibrate and amlodipine.⁵

• There is an association with hepatitis B, in which case treatment of the hepatitis may improve the skin.

Schamberg's disease symptoms⁴

There are no symptoms of Schamberg's disease apart from itching and patients noting their skin looks blotchy. For some this is enough to cause psychological distress. However, some patients have reported pains in their limbs - which may be coincidental.

Lesions are most commonly on the lower limbs bilaterally but can occur anywhere or be unilateral. A case involving the genitals has been reported.

The lesions consist of:

• Asymmetrical brown/orange patches.

• Non-blanchable purpura.

• Petechiae called 'cayenne pepper spots' (develop at the edge of old lesions).

Patterns can vary - for example, annular, linear. There may also be associated lichenification, scaling and pruritic marks.

אבחנה מבדלת¹⁶

Other causes of pigmented purpura include:

• וסקוליטיס - for example, leukocytoclastic vasculitis.

• לימפומה של תאי T (especially if presenting in young males).

• Drug eruption.

• Trauma.

• Self-induced purpura or non-accidental injury to a child.

• Purpura annularis telangioectodes (Majocci disease).

• Mycosis fungoides.⁷

• Primary benign hypergammaglobulinaemic purpura of Waldenström.⁸

חקירות

• Blood tests - including platelets and clotting - are usually normal.

• Autoantibody screen and hepatitis serology should be performed.

• Skin biopsy - histology reveals a capillaritis of dermal vessels. Other changes that may be seen include perivascular inflammatory infiltrate, endothelial hypertrophy with extravasation of blood cells and haemosiderin-laden macrophages.⁹

• Examination of the skin, using a dermatoscope, may be helpful although there are limited reports in the literature.¹¹⁰

מחלות נלוות^{11 12}

• סוכרת.

• דלקת מפרקים שגרונית.

• זאבת אדמנתית מערכתית.

• הפרעות בבלוטת התריס.

• Hepatic disease, including hepatitis B.

• פורפיריה.

• ממאירויות.

• Dyslipidaemias.

Schamberg's disease treatment and management^{1 4 11}

Any suspected precipitants should be withdrawn.

• Pruritis - treat with mild topical corticosteroid or antihistamines.

• Good results have been obtained with narrow-band ultraviolet light.

• Aminaphtone, a drug normally used in other venous conditions such as chronic venous congestion of the lower limbs can be used.¹³

• Superimposed infection - will need antibiotics.

• Systemic steroids provide some benefits but these are outweighed by the risks of systemic side-effects.

• Advanced fluorescent technology using pulses of light has produced some promising cosmetic results.¹⁴¹⁵

Other tried treatments include vitamin C supplements, laser therapy and wearing support hosiery to prevent venous stasis. There is no evidence from randomised blinded trials of definite benefit of the former two, although case studies exist suggesting benefits from both. Immunosuppressants have also been used. PUVA treatment has been used successfully.²

תחזית

Schamberg's disease usually runs a chronic course with frequent exacerbations and remissions. The rash may be present for many years with slow extension. Pigmented purpura may occasionally disappear spontaneously.

The development of T-cell lymphoma in patients with Schamberg's disease has been reported.¹⁶