Subcutaneous nodule

Introduction The subcutaneous nodules are a hard, round or elliptical, painless nodule. The diameter is 0.2 to 10 cm, and it is often located in more parts of the friction, such as the elbow extension, the Achilles tendon, the scalp, the ischial tuberosity or the joint. Unusual parts have ears and bridge of the nose. Subcutaneous nodules rarely cause symptoms, occasionally rupture or complicated infection. Typical subcutaneous nodules grow slowly, persist or disappear when the disease is relieved. The appearance of subcutaneous nodules is closely related to high titer serum rheumatoid factor, severe joint destruction and rheumatoid active lesions.

Cause

It is characterized by bilateral occurrence, but asymmetry, the diameter of the nodules is 0.5~2.0cm, the hardness is hard and tender, the surface skin can be yellow-red, bright red or normal skin tone, and the nodules can be single or multiple, along the table The superficial arteries are arranged or clustered in the vicinity of the blood vessels, and they can resolve spontaneously for more than one week. Such nodules can also occur on the trunk, face, shoulders, etc., sometimes at the same time as the reticular leukoplakia. The blue or pink tender nodules appearing at the fingertips, toes, and large and small fish muscles are called osier nodules and can be found in infective endocarditis.

Pay attention to size, hardness, location, mobility, and tenderness when examining subcutaneous nodules. Located near the joint, the long bones end, the round hard nodules are mostly rheumatism no knot, no tenderness.

1 cystic nodules: soy, limbs, subcutaneous or intramuscular appearance of soybean-to-walnut-sized nodules, mostly pork aphid cystic nodules, characterized by round or oval, smooth surface, no tenderness, and skin No adhesion, can be pushed, texture is tough, but there is a certain degree of elasticity, the number is different (less than 1 to 2, as many as hundreds), this nodule can also be seen in the neck, breast and genital subcutaneous.

Type 2 rheumatoid nodules: a small number of nodules at joints and bone bulges are often rheumatoid nodules, which are mainly caused by accumulation of fibrin-like substances in the subcutaneous tissue and/or dermis and tissue cells. . Its characteristics are harder than rubber, more no tenderness, ranging in size from a few mm to 2 cm, adhesion or non-adhesion to the skin, occurs in the back of the elbow, knuckles, shoulder bones, occipital process, gastrocnemius tendon, etc. .

3 gout nodules: also known as tophus (tophus) is the blood uric acid exceeds the saturation concentration, urate needle crystals deposited in the subcutaneous connective tissue, causing a chronic foreign body-like reaction. Generally, the ear wheel, the ear wheel, the toe, the finger joint and the metacarpophalangeal joint of the outer ear are more common. Yellow-white nodules of varying sizes (small to small grain, as large as 1 to 2 cm), or asymptomatic, or painful. On the surface of larger nodules, the skin becomes thinner and ruptured to discharge white-like substances, which are not suitable for healing. Secondary infections are rare and are characteristic lesions of gout.

4 nodular erythema (erythema nodosum): more common in young women, occurs in the calf stretch side, often symmetrical, different sizes (diameter l ~ 5 cm), the number varies (2-50 or more) Painful nodules. The nodules occur faster, slightly higher than the leather surface, the skin is tight, there may be edema around, and the surface is hot and tender. Skin lesions change from bright red to purple, and finally yellow. It usually lasts for several days to several weeks and gradually subsides. It does not cause ulcers and scars, but it is easy to relapse. It can be found in infections such as hemolytic streptococcus, autoimmune diseases, certain drugs (such as bromine agents, oral contraceptives, etc.) and leprosy. Some nodules gradually increase from isolation, the course of disease lasts for several years, the nodule inflammation is mild, and the tenderness is light, called chronic nodular erythema.

5 panniculitis nodules: the size of the thighs is different (the diameter can be 0.5 ~ l0cm or more), medium hardness, clear boundary, tenderness, adhesion to the skin (small activity), can last for more than a few weeks Subcutaneous nodules with skin depression and pigmentation after regression are mostly manifestations of panniculitis.

6 Others: It occurs in the lower limbs and upper limbs. The lesions are confined to the subcutaneous tissue. The nodules of the small arteries are often the manifestations of nodular polyarteritis.

an examination

Related inspection

Blood routine spiral CT examination CT examination

Pay attention to size, hardness, location, mobility, and tenderness when examining subcutaneous nodules. Located near the joint, the long bones end, the round hard nodules are mostly rheumatism no knot, no tenderness.

Differential diagnosis

The skin manifests in a variety of forms, often papules, nodules, plaques, erythroderma, psoriasis, scarring sarcoidosis, hypopigmentation and baldness. Skin lesions are distributed asymmetrically on the face and limbs. The rash is hard and elastic, gradually spreading to the skin, involving the thickness of the entire dermis. The changes in the epidermis are not obvious, and can be slightly thinned, discolored, telangiectasia and a little scale. Often it is light red to purple brown, not broken, no symptoms.

(1) Papular sarcoidosis: The lesion is a small nodule of needle-to-pea size, also known as a miliary-like sarcoidosis. Mainly distributed on the face, neck and shoulders. When the slide is pressed, it shows a pale yellow spot similar to lupus nodules, leaving no trace after disappearing, sometimes leaving pigment spots, atrophy and scars.

(2) Plaque-type sarcoidosis: Hutchinson first reported this unique plaque lesion, a large lobulated nodular plaque with a flat surface and a slightly elevated surface, common in the buccal, nasal and arm.

(3) Psoriasis-like sarcoidosis: Plaques with clear boundaries on the trunk and extremities are often present, with psoriasis-like scales on them.

(4) Frostbite-like lupus type: In the parts prone to frostbite, such as ear, pregnancy, cheeks, nose, and toes, symmetry occurs in the shallower red or purple-red plaque.

(5) Subcutaneous sarcoidosis: Also known as Darier-Roussy sarcoidosis. The solid subcutaneous nodules from the beans to the chestnuts adhere to the skin, and the epidermis is mildly ochre. It is common in the trunk, and the face is rare and has no symptoms.

(6) Scar mesenroma: Damage occurs in the scar area. Such as burns, folliculitis, and scars after herpes zoster. The original scar area is enlarged and the height is increased, which is similar to keloid.

(7) erythrodermic mesothelioma: diffuse distribution of invasive erythema and scaly patches with unclear borders.

(8) Nodular erythematous belloid tumor: some patients with sarcoidosis with multiple joint pain with fever, increased erythrocyte sedimentation rate, X-ray examination of hilar lymphadenopathy. Painful subcutaneous nodules occur on the face, back, and extremities. The skin on the surface is red, most common in young women.

(9) Mucosal mesothelioma: Oral hard palate, buccal, uvula and tonsil needles, clusters formed into flat plaques, small nodules in the conjunctiva and lacrimal glands.

(10) Other skin lesions: Sarcoidosis may be associated with subcutaneous calcinosis, pruritus, erythema multiforme, and folliculitis. Skin atrophy, hyperkeratosis, increased or decreased pigmentation can also be caused by the disease.

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