Schamberg's Disease

Synonyms: Progressive pigmented purpuric dermatitis, Gougerot-Blum capillaritis, itching purpura, pigmented purpuric eruption.

Schamberg's disease was first described in 1901 in a 15 year old boy by Schamberg. It represents a benign dermatoses with purpura due to leaking from capillaries close to the skin surface. It most often effects the legs and spreads slowly. The discoloration is brown / orange due to haemosiderin deposition in the skin.
Pigmented purpuric reactions have five disease types:^{1 2}

• 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 PUVA.
• Purpura annularis telengiectoides - rare, preponderance in young females and manifests as annular erythematous plaques and patches.
• Eczematoid-like purpura of Doucas and Kapetenakis - occurs in men with bilateral intensely itchy lesions on legs.
• Lichen aureus - a localized persistent form of pigmented purpuric dermatitis³

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

More common in males and can occur at any age. It has been stated as the commonest cause of petechiae in children¹ - however, it is thought that this may not actually be the case.⁴ There has been a case report of four family members with Schamberg's disease suggesting a possible genetic link.⁵

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

• Recent viral infection
• 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.⁶ It has also been reported in bezafibrate.⁶

There are no symptoms apart from itching - except patients note 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. They consist of

• Asymmetrical brown / orange patches
• Purpura
• Non-blanchable
• Petechiae called "cayenne pepper" spots(develop at the edge of old lesions)

Patterns can vary e.g. annular, linear.
There may be associated lichenification, scaling and pruritic marks.

• Other causes of purpura
• Vasculitis e.g. leukocytoclastic vasculitis
• T-cell lymphoma (especially if presenting in young males)¹
• Drug eruption
• Trauma
• Self-induced purpura
• Mycosis fungoides⁷

• 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.¹

• Diabetes mellitus
• Rheumatoid arthritis
• SLE
• Thyroid abnormalities
• Hepatic disease
• Porphyria
• Malignancies
• Dyslipidaemias

There is no cure for Schamberg's disease - any suspected precipitants should be withdrawn.

• Itching - treat with mild topical corticosteroid or antihistamines
• Superimposed infection - will need antibiotics
• Systemic steroids - no real evidence of their benefit¹

Other tried treatments include vitamin C supplements, laser therapy and wearing support hosiery to prevent venous stasis.² There is no evidence of definite benefit of the former two. Immunosuppressants have also been used.²
Psoralen therapy has been used but the number of cases with successful outcomes is few.²

Schamberg's disease usually runs a chronic course with frequent exacerbations and remissions.The rash may be present for many years with slow extension. Lesions may occasionally disappear spontaneously.
There has been three reports of patients with Schamberg's disease developing T-cell lymphoma.¹