Cosa sono le manifestazioni cutanee?

La pelle può essere colpita da una vasta gamma di condizioni sottostanti ed è sempre importante considerare questa possibilità quando un paziente presenta una lesione cutanea che non ha una diagnosi chiara come dermatite o psoriasi. Questo articolo fornisce una panoramica di alcune delle condizioni più comunemente riscontrate nella pratica che possono manifestarsi con cambiamenti nella pelle.

Skin manifestations of iperlipidemia include flat yellow deposits around the eye (xanthelasmata). Elsewhere on the body they present as yellowish papules or nodules called xanthomata. Sudden eruptions can appear in large numbers over the buttocks, trunk and limbs, or a few larger lesions can develop on the elbows, knees, hands and over the Achilles tendon.

Malattia infiammatoria intestinale

Manifestazioni cutanee riscontrate nella malattia infiammatoria intestinale (morbo di Crohn, colite ulcerosa) can include pioderma gangrenoso e eritema nodoso.² Oral manifestations include aphthous stomatitis, mucosal nodularity (cobblestoning) and pyostomatitis vegetans (erythematous thickened mucosa).³

Sindrome carcinoide

Cutaneous metastases in sindrome carcinoide can present as deep nodules, hyperkeratosis and pigmentation changes similar to those seen in pellagra.⁴

Recurrent skin infections are common with diabete mellito, either due to fungi (eg, candidosi genitale) or bacteria (eg, follicolite). Blisters and granuloma anulare may be found on the feet.⁵

A volte si sviluppano macchie marroni sulla tibia; quando queste formano vesciche, la condizione è chiamata bullosi diabeticorum.⁶ Necrobiosi lipoidica diabeticorum can also occur on the shins. The lesions have the appearance of plaques with dark red or purple edges, atrophic centres and surface telangiectasias.

Le manifestazioni cutanee includono caratteristicamente:

• Ittero.

• Eritema dei palmi.

• Porpora.

• Angiomi stellati.

• Prurito generalizzato.

Lichen planus is known to be linked to infezione da epatite C.⁷

A variety of skin conditions can occur in virus dell'immunodeficienza umana (HIV)/sindrome da immunodeficienza acquisita (AIDS).

Dermatite

The appearance can resemble psoriasi, artrite reattiva oppure dermatite seborroica and has been termed 'psoriasiform dermatitis of AIDS'.

Infezioni

Bacillary angiomatosis is a treatable infection caused by a rickettsia-like organism similar to Rochalimaea quintana - the agent of febbre delle trincee. Viral infections such as chronic herpes zoster can also occur.⁹

Malignità

Sarcoma di Kaposi is an AIDS-defining illness characterised by initial bruise-like macules developing into brown-red or purple firm-to-hard nodules. In AIDS these are widespread, especially on the face and trunk.¹⁰

Sarcoidosi can present with eritema nodoso, o con placche, papule o noduli. Questi ultimi sono comunemente visti come lesioni lisce, marrone scuro/violacee disposte in un pattern anulare. L'infiltrazione di una vecchia cicatrice è caratteristica, così che diventa di un colore viola brillante. Il lupus pernio è una forma che si sviluppa lentamente e si diffonde in ampie aree di placca sul mento e sul naso.

Mastocitosi is a condition in which there is proliferation of mast cells. In the skin it can cause single or multiple, dark red nodules or plaques that develop into a blister or wheal when rubbed. This is at its most common in babies. It can also cause urticaria pigmentosa, either as skin wheals in infancy often following a bath, or as extensive areas of dark brown macules that swell and go red when stroked in adults.

Amiloidosi appears in middle age with bruising, petechiae and purpura related to deposition of amyloid in the dermal blood supply. This is most frequently seen in the anogenital, periorbital and peri-umbilical regions, at the side of the neck and in the axillae. Atrophic waxy lesions with areas of purpura inside them may sometimes be seen, and the tips of the fingers may exhibit softening and loosening of the skin. A case of advanced primary amyloidosis presenting as a non-healing leg ulcer has also been reported.¹⁴

L'amiloidosi cutanea è associata a vari disturbi autoimmuni/di immunità, e sono state riportate associazioni con sarcoidosi e nefropatia da IgA.¹⁵

Cutaneous changes in acromegalia can include skin puffiness, oily skin with large pores, hypertrichosis, pigmented skin tags, acanthosis nigricans and psoriasis.¹⁶ Skin creases in the head area are deeper than normal (cutis verticis gyrata, or 'Klingon head').¹⁷

In ipopituitarismo the skin is often dry, scaly and puffy and the nails become brittle. The hair is coarse and sparse, especially in the axillae. Fine wrinkles around the eyes and mouth are typical.

In ipotiroidismo the skin in myxoedema is cool to the touch, doughy, dry and puffy and there may be hair loss. Peri-orbital oedema may be accompanied by a yellowish colour to the skin.

In ipertiroidismo the skin is warm and moist and flushing of the face and palms is sometimes seem. Pretibial myxoedema is is an autoimmune manifestation of Graves' disease, but also occasionally occurs in tiroidite di Hashimoto.

In sindrome di Cushing abdominal striae may be a prominent feature, caused by skin atrophy. The skin may bruise easily and skin infections and acne may be frequent problems. Skin darkening may occur in the palmar creases, on areas subject to pressure and in the axillae.¹⁸

L'insufficienza surrenalica primaria (morbo di Addison) causa iperpigmentazione, particolarmente evidente nella mucosa buccale, labbra, pieghe palmari, nuove cicatrici e in aree soggette a pressione come gomiti, nocche e ginocchia. I cambiamenti non sono presenti nell'insufficienza surrenalica secondaria.

There are a number of different forms of porfiria - eg, porphyria cutanea tarda, erythropoietic porphyria.^{22 23} All are characterised by photosensitivity, with fragility and blistering of the skin when exposed to sunlight or ultraviolet rays.

Rheumatoid nodules - subcutaneous lumps seen near an affected joint - occur in about 25% of patients with artrite reumatoide. Other phenomena include thinning of the skin, translucency of the skin on the back of the hands, brittle nails which split lengthwise and reddened palms (palmar erythema). Dermatitis in which neutrophils are prominent on biopsy (neutrophilic dermatosis) may present as erythematous areas and interstitial granulomatous dermatitis is a rare condition in which rheumatoid papules may appear on the trunk. Cutaneous vasculite may present as purpuric areas on the skin.

Keratoderma blennorrhagicum is sometimes seen in artrite reattiva. È caratterizzato da lesioni ipercheratosiche sui palmi delle mani o sulle piante dei piedi. Si sviluppano vescicole chiare su una base eritematosa che poi progrediscono in macule, papule e noduli. Le lesioni possono essere impossibili da distinguere dalla psoriasi pustolosa.²⁵

In sindrome mielodisplastica various cutaneous manifestations can occur, including leukaemia cutis, photosensitivity, prurigo nodularis and purpura. Cutaneous conditions are thought to indicate that the patient belongs to a high-risk group, associated with bone marrow transformation and hypergammaglobulinaemia.²⁶