Manifestations of Systemic Diseases

Dermatology Dr. Ahmed Abdulhussein Alhuchami

2020

The cutaneous manifestations of systemic diseases

Many systemic diseases show a specific eruption on the skin, which may give a clue to the diagnosis of the underlying systemic disease; yet, some diseases affect both the skin & other organs at the same time.

DIABETES & THE SKIN:

In diabetes, the skin shows many features, the most important of which are:

1- Infections: diabetics are more prone to all types of infections especially bacterial such as staphylococcal, E-coli, & pseudomonas, fungal infections especially by candida albicans & in many instances; cutaneous candidiasis may actually lead to the diagnosis of diabetes.

2-Diabetic dermopathy (shin spots) which are the most common cutaneous sign of diabetes affecting about 50% of patients with diabetes, mostly men, consisting of dull-red papules that progress to well-circumscribed, small, round, atrophic, hyperpigmented lesions on the shins.

3- Diabetic bullae: non-inflammatory, painless, blistering, most often in acral locations is characteristic in diabetes; these usually heal spontaneously without scarring within 4-5 weeks.
4- Ulceration: especially on the feet due to neuropathy & impaired circulation, such ulceration on the neuropathic, microvascularly compromised, & infection prone diabetic foot may pose a threat to both life & limb of the patient.

5-Carotenosis: yellowish discoloration of the skin especially on palms & soles, the sclera usually remain white.


6- necrobiosis lipoidica (necrobiosis lipoidica diabeticorum):

A well-circumscribed, depressed, waxy, firm lesion with a sulfur yellow centre surrounded by a broad violaceous border, with numerous telangectasia in the yellow portion, ulceration is not unusual; female to male ratio is 3:1, the shins are affected in 85% of cases.

7- Granuloma annulare: The association with diabetes is questionable especially in the

generalized type, asymptomatic dermal nodules occur singly or in an annular configuration, usually on hands & feet, they show spontaneous resolution within months to few years.

8-Eruptive xanthomas, & porpyria cutanea tarda.

9- Acanthosis nigricans.

10- Many other minor complications.

THE SKIN IN LIVER DISEASES:

Many cutaneous manifestations can be seen in a patient with liver disease, the most important of which are:
1- Pruritis: usually related to obstructive jaundice, but may precede it.
2- Jaundice.
3- Spider nevi: often multiple in chronic liver disease.
4- Palmar erythema.
5- White nails: these are associated with hypoalbuminaemia.
6- Porphyria cutanea tarda: characterized by formation of bullae, scarring & dyspigmentation on the sun-exposed skin, there is a defect in the heam synthesis pathway with enzyme deficiency (uroporphyrinogen decarboxylase) resulting in an increase in the intermediate metabolites of heamoglobin (porphyrin) which is deposited in the skin, teeth &excreted in the urine of patients.
7- Xanthoma: in primary biliary cirrhosis.


THE SKIN IN RENAL FAILURE:

The main changes are:

1- Pruritis & a generally dry skin.
2- Pigmentation: earthy color with a yellowish tinge & pallor from anaemia.
3- Half & half nails, with the proximal half white & the distal half pink or brown.
4-Infections: such as onychomycosis & tinea pedis
5- Xanthoma.

THE SKIN IN THYROID DISEASE:

patients with thyroid disease may show numerous skin changes, some of which may at times be the first clinical signs.

Cutaneous manifestations of hypothyroidisim:

1- Dry & pale skin.
2- Oedema of eyelids & hands.
3- Decreased sweating.
4- Hair changes: coarse, thin, brittle hair with loss of pubic, axillary hair, & the outer third of the eyebrows.
5- Brittle & poorly growing nails.
6- Purpura & bruising.

HYPERTHROIDISM:

1- Pretibial myxoedema: plaques & nodules on the skin of shins which are non pitting on pressure.
2- Increased sweating (hyperhidrosis): especially of palms & soles.
3- Facial flushing.
4- Palmar erythema.
5- Thinning of scalp hair.
6- Rapidly growing nails with sometimes clubbing.
7- Diffuse pigmentation.


CUSHING SYNDROME: this causes similar features to the side effects of systemic steroids, these include: truncal obesity, moon face, striae distensiae, hypertension, decreased carbohydrate tolerance, protein catabolism, psychiatiric disturbances, amenorrhoea & hirsutism in females.

XANTHOMAS: Are deposits of fatty material in the skin, subcutaneous fat & tendons which may be the first clue to primary or secondary hyperlipidemia, the primary type is genetically determined with many groups. Secondary hyperlipidemia is seen in different diseases such as diabetes, primary biliary cirrhosis, nephrotic syndrome, hypothyroidism, obesity, pancreatitis, chronic renal failure, & treatment with drugs such as estrogens, systemic steroids & retinoids

Various clinical forms of xanthoma are seen:

1- Xanthelasma palpebrarum: these are small yellow grey flattened plaques around the eyes, especially near the inner canthus, they are the most common form of xanthomas

2- Tuberous xanthoma: yellowish or orange firm nodules found mostly over joints such as elbows & knees.

3- Tendinous xanthoma: subcutaneous nodules attached to tendons, especially those on the dorsal aspect of fingers & the Achilles tendon.

4- Eruptive xanthoma: small, yellowish to reddish papules that appear in crops all over the body especially the shoulders & buttocks.

5- Plane xanthoma: flat macules or slightly elevated plaques with a yellowish-orange color, they may occur anywhere on the skin especially the palmar creases, inner thighs & axillae.

The morphologies of xanthomas are relatively specific for the associated elevated lipid, with the eruptive xanthoma seen mostly with hyper- triglyceridemia & other forms seen with elevation in cholesterol.