OVERVIEW
Xanthomatosis is a skin disorder characterized by a limited accumulation of lipid-containing tissue-foam cells in the dermis, subcutaneous tissue, and tendons, resulting in the formation of cutaneous tumor-like lesions such as brownish-yellow or orange-yellow patches, papules, or nodules. It occurs in patients with hyperlipoproteinemia and is a common and diagnostic skin manifestation in these patients.
Etiology
The cause of the disease is unclear. In patients with hyperlipoproteinemia, elevated lipids are the main cause, and lipids are deposited in the tissues and phagocytosed by the tissue cells to form tissue-foam cells (i.e., xanthomatous cells), which aggregate to form xanthomas.
Classification
It can be divided into primary xanthomatosis and secondary xanthomatosis, and the former can be divided into familial and non-familial. Familial xanthomatosis often has different degrees of lipid metabolism disorders and systemic manifestations, while non-familial xanthomatosis is often disseminated, and usually has no lipid metabolism abnormalities and systemic manifestations. Secondary xanthomatosis refers to xanthomatosis caused by abnormal lipid metabolism of other diseases, such as diabetes mellitus and lymphoma.
Symptoms
Skin lesions are yellow, brownish-yellow, orange or yellowish-red papules, nodules and plaques, and patients mostly have no conscious symptoms, which can be classified into various types.
1. Blepharoplasty
Also known as eyelid warts, it is the most common type of xanthomatosis, which occurs in middle-aged women. Skin damage occurs in the inner canthus of the upper eyelid, symmetrical distribution, for the soft orange rectangular or polygonal rash or plaque, can be single or multiple presence, a few can be fused to horseshoe, can be a long time, and seldom self-healing. Patients mostly have no conscious symptoms, often accompany with other types of xanthomas, and may also appear in patients with various types of familial hyperlipoproteinemia, especially in patients with familial hypercholesterolemia.
2. Tendon xanthoma
Skin damage occurs in the Achilles tendon and extensor tendons of hands and feet, and also occurs in the periosteum of the ankle, tibial tuberosity and elbow etc. It is not adherent to the skin, and the skin on it is normal. This disease is common in patients with familial high cholesterol.
3. Nodular xanthoma
Skin damage occurs in the joint extensor surfaces, with elbow and knee joints being the most common ones, and it can also involve ankle joints, finger (toe) joints, armpits, groin, face, buttocks and mucous membranes. early stage of the disease is corn-grain papules, yellowish or orange-yellow nodules of soft texture, and it can become flat or elevated round nodules of solid texture along with the fibrous hyperplasia, and some of them can be fused to form plaques of up to 5cm in diameter. patients often have no conscious symptoms, and it can be seen in familial hypercholesterolemia and familial anomalies. It can be seen in patients with familial hypercholesterolemia and familial abnormal β-lipoproteinemia.
4. Rash xanthoma
Skin damage occurs in buttocks, shoulders, hands and extensor side of arms and knees, which are yellow or orange papules appearing in batches or occurring suddenly, with obvious inflammation in acute stage, surrounded by red halo, accompanied by itching or pressure pain, and there may be isomorphic reaction, and it may subside on its own after a few weeks, with pigmented or hypertrophic scars. Most common in hypertriglyceridemia, mixed hypertriglyceridemia and plasma very low-density lipoprotein or celiac particle concentration increased patients, can also occur in secondary hyperlipoproteinemia and diabetes mellitus.
5. Flat xanthoma
Skin lesions can occur in any part of the body, which are yellow or orange spots or flat plaques with clear boundaries, and can be divided into subtypes of diffuse flat xanthoma, palmar (striated) xanthoma, interstitial xanthoma, cholestatic flat xanthoma and so on.
Examination
1. Physical examination
The characteristic yellow or orange patches, papules or nodular skin lesions of each type of xanthomatosis can be seen.
2. Blood biochemical examination
Most patients may have elevated plasma lipoprotein levels.
3. Histopathologic examination
A large number of foamy histiocytes infiltrate the dermis, the collection is nodular or diffusely distributed, sparse lymphocyte infiltration around blood vessels, and the epidermis is generally thinned.
Diagnosis
Pay attention to the collection of the patient’s medical history, there may be familial hyperlipoproteinemia; physical examination can be seen characteristic yellow or orange patches, papules or nodular skin damage, the diagnosis can be made; histopathological examination can help to confirm the diagnosis.
Differential diagnosis
1. Nodular disease
The histopathological examination of this disease shows granulomas of epithelioid cells of varying sizes in the dermis, with little lymphocytic infiltration around them, showing “bare nodules”.
2. Langerhans cell histiocytosis
The histopathological examination of this disease shows granulomatous changes composed of histiocytes, multinucleated giant cells, eosinophils, lymphocytes and plasma cells, and the immunohistochemical staining of histiocytes is positive for S-100 protein and CD1a.
Treatment
Choose a low-fat, low-sugar, high-protein diet, and oral lipid-lowering drugs for patients with hyperlipidemia. Systemic therapy may include drugs that affect cholesterol and bile salt absorption, drugs that alter lipoprotein synthesis and catabolism, and drugs that affect endogenous cholesterol synthesis. Electrocoagulation, liquid nitrogen freezing, carbon dioxide laser can be chosen for lid xanthomas and smaller xanthomas, and surgical excision is feasible for larger xanthomas.
Prognosis
The prognosis of xanthomatosis is good, it can be improved or cured by treatment, but there is a possibility of recurrence.