Criteria for diagnosis
histopathologically: An acanthotic epidermis that is covered in part by
staggered mounds of parakeratosis housing numerous neutrophils and
elongated dermal papillae containing dilated tortuous capillaries
and lymphocytes around venules of the superficial plexus sum up to
the diagnosis of psoriasis.
Differential diagnosis histopathologically:
There is none.
Criteria for diagnosis clinically: A
diffuse erythema covered by coarse scales that have a raised edge
is the presentation of psoriasis at the erythrodermic stage. Gross
examination of the nails and joints can help to come to a correct
diagnosis when changes of psoriatic onychopathy and or psoriatic
arthritis are present.
Differential diagnosis clinically: Other diseases can clinically present as erythroderma,
including mycosis fungoides, pityriasis rubra pilaris, drug
eruptions, atopic dermatitis, and allergic contact dermatitis.
Therefore, a skin biopsy is necessary to come to the correct
Clinico-pathologic correlation: The erythema is related, in large measure, to dilation
of venules and capillaries in the upper part of the dermis. The
scale-crust is a manifestation of the zones of hyper- and
parakeratosis that contain many neutrophils.
Options for therapy
predicated on knowledge of histopathologic findings:
There are different treatment options for
erythrodermic psoriasis. The severity of disease, the course (acute
onset or chronic disease), and the presence of comorbidities have
to be taken into consideration when choosing a particular therapy.
Cyclosporine and infliximab seem to have the most rapid onset of
action. Alternatively, acitretin and methotrexate can be used, but
these drugs work more slowly and might be only effective in
combination with other therapies.
Erythroderma is one of the various clinical expressions of
psoriasis. Histopathologically the typical changes of fully
developed psoriasis are present: dilated tortuous capillaries in
thin dermal papillae, edema of the papillary dermis, a thinned
granular zone, epidermal pallor, psoriasiform hyperplasia, an
increased number of mitotic figures in the suprabasal layer of the
epidermis, and a sparse lymphocytic inflammatory infiltrate in the
upper part of the dermis.
erythrodermic psoriasis the proliferation of keratinocytes is
dramatically increased, and this severely affects their
differentiation, leading to a near absence of a cornified layer and
to the presence of viable keratinocytes instead of
3) The near
absence of scale in an otherwise typical lesion of psoriasis is a
clue to erythrodermic psoriasis. The absence of mounds of
parakeratotic cells might be due to exfoliation or to an artefact
caused by fixation of specimens with formalin.