What is Calcinosis Cutis?
Calcinosis cutis is a condition where calcium salts build up in the skin and the layer just underneath the skin, known as subcutaneous tissue. There are five main types: dystrophic, metastatic, idiopathic, iatrogenic, and calciphylaxis.
Dystrophic calcification is the most common type and is usually linked with normal calcium and phosphorus levels in the body. It usually happens when there’s another disease present, like systemic sclerosis, dermatomyositis, mixed connective tissue disease, or lupus, that damages tissue and sets the stage for calcification, or the buildup of calcium.
Metastatic calcification happens when calcium and phosphorus levels in the body are too high, causing the deposit of calcium salts once the combined product of calcium and phosphorus exceeds a certain level (70 in this case). Idiopathic calcification happens without any obvious tissue damage or irregular lab results, and it includes conditions like tumoral calcinosis, subepidermal calcified nodules, and scrotal calcinosis.
Iatrogenic calcification is caused by the intake of a product containing calcium or phosphate that causes calcium salts to be precipitated, or deposited. Calciphylaxis involves the calcification of small to medium-sized blood vessels and is typically a result of chronic kidney failure and dialysis.
If the disorder only affects a limb or joint, it’s called calcinosis circumscripta. If it impacts wide-spread areas of muscles and tendons along with subcutaneous structures, it’s referred to as calcinosis universalis.
What Causes Calcinosis Cutis?
Calcinosis is a condition where calcium deposits form in various parts of the body. This can be caused by many things, including injuries, inflammation, varicose veins (swollen and twisted veins), tumors, infections, diseases affecting our connective tissue, having too much phosphate in the blood (hyperphosphatemia), and having too much calcium in the blood (hypercalcemia).
There’s a specific type of this condition called Calcinosis cutis, which is often linked to a disease called systemic sclerosis. This disease causes hardening and tightening of the skin and connective tissues in the body.
Risk Factors and Frequency for Calcinosis Cutis
Calcinosis cutis is a condition often seen in people with systemic sclerosis, especially a form known as ‘CREST.’ Between 25% – 40% of people with this form of sclerosis will develop calcinosis cutis within ten years of diagnosis. This condition is also present in 30% of adults and up to 70% of children and teenagers with dermatomyositis, a skin condition. Furthermore, up to a third of patients with systemic lupus erythematosus can show signs of calcification around joints, and soft tissue calcification in 17% of cases.
Signs and Symptoms of Calcinosis Cutis
Dystrophic calcification is a condition where lesions or abnormal tissue can form slowly without any symptoms, or it can spread quickly and be more severe. These lumps can change in shape and size and could cause pain, which may affect your movement. The location of these lesions depends on the specific underlying disease causing the dystrophic calcification. Here are typical locations for some of these conditions:
- In systemic sclerosis, lesions commonly appear on the forearms, elbows, fingers, and knees.
- In dermatomyositis, the calcification happens in elbows, knees, and areas where there were previous inflammatory lesions.
- In lupus erythematosus, the extremities, buttocks, underneath lupus lesions, and areas around joints are usually affected.
- In metastatic calcification, lesions typically form around joints.
- In tumoral calcinosis, lesions also appear around joints.
- In subepidermal calcified nodules in idiopathic calcification, lesion source to appear on children’s faces.
- In iatrogenic calcification, calcification is usually found at sites where veins have been punctured for medical treatment.
Testing for Calcinosis Cutis
To understand and assess your health condition, your doctor may order several lab tests and imaging procedures to identify the cause and how far it has progressed.
Blood tests are typically the first step – A ‘complete blood count’ checks for various illnesses including lupus erythematosus (an autoimmune disease) and possible cancerous tumors.
Another test called a ‘basic metabolic panel’, which includes measuring creatinine and urea levels in your blood, can tell doctors if the kidneys are working properly. Tests for parathyroid hormone and vitamin D levels can help rule out two conditions – hyperparathyroidism (overactive parathyroid glands) and hypervitaminosis D (too much vitamin D).
For a condition called metastatic calcification (abnormal calcium deposits in body tissues), your physician may order tests for calcium, phosphate, total proteins, albumin, and your body’s 24-hour levels of calcium and inorganic phosphate.
To evaluate for dermatomyositis (a disease causing inflammation and weakness in muscles), tests for creatine phosphokinase (CPK), lactate dehydrogenase (LDH), glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and aldolase will be done.
For lupus and systemic sclerosis (a disease that results in hard, tight skin and damage to internal organs), tests for antinuclear antibodies (ANA), anti-dsDNA, and anti-ENA will be done. Anti-ENA is a test that checks for different proteins in the blood that are produced by the immune system.
The last set of tests, involving bicarbonate and arterial pH can be performed to rule out milk and alkali syndrome, a condition caused by consuming large amounts of calcium and absorbable alkali.
In addition to these lab tests, your doctor may order imaging studies to get a more detailed view of the affected area. This could include an X-ray, skin ultrasound, bone scintigraphy (a type of bone scan), CT scan, MRI, or a skin biopsy.
Treatment Options for Calcinosis Cutis
Treating calcinosis cutis, a condition where calcium deposits form in the skin, can be quite tricky. There are some things you can do to help make treatment more successful and improve blood flow to your hands and feet. It’s essential to avoid injury, stop smoking, minimize stress, and keep away from the cold. Smaller calcified areas might respond to a variety of medications like warfarin and ceftriaxone, or to a treatment called intravenous immunoglobulin (IVIG), a protein that helps your body fight infections. Surgery or a type of laser treatment may also be useful.
In the case of larger calcified areas, different medications such as diltiazem, bisphosphonates, and probenecid might work. Treatment could also include aluminum hydroxide or surgery. Surgery is a good option for patients with small and localized calcium deposits; meanwhile, for more widespread cases, medications are often the way to go.
The most commonly used treatment for calcinosis cutis is a medication called diltiazem. This drug works by lowering the amount of calcium entering the cells and macrophages (a type of white blood cell) of the damaged tissues.
Warfarin is also another possible treatment option. In some patients with calcinosis cutis, the levels of vitamin K, which is important for blood clotting, are high. However, taking warfarin can bring these levels back down to normal and improved small calcified areas.
Bisphosphonates are another group of drugs that can be beneficial. They primarily work by targeting active macrophages at the affected sites, reducing the release of certain inflammation-causing substances, and decreasing calcium turnover and overall calcium absorption.
Some other medications that could be used include minocycline, ceftriaxone, and aluminum hydroxide. Minocycline can help reduce inflammation and also bind to calcium. Ceftriaxone has anti-inflammatory properties and can bind to calcium as well, while aluminum hydroxide can bind to phosphorous, reducing its absorption from the gut. Both minocycline and ceftriaxone have shown effectiveness in cases of systemic sclerosis, a disease that leads to hard, tight skin, and damage to internal organs. On the other hand, aluminum hydroxide has been useful in treatment with patients having calcinosis cutis as a part of dermatomyositis and lupus, autoimmune diseases that cause inflammation and damage to the skin, joints, and various internal organs.
Topical sodium thiosulfate is used because it can increases calcium solubility. It has been shown effective in treatment of ulcerated, hardened calcified areas when mixed with zinc oxide. The injection form of sodium thiosulfate has been used successfully to treat calcinosis cutis in a patient with lupus panniculitis, a rare skin manifestation of lupus. It has also been used intravenously to treat calciphylaxis, a serious skin condition with hardened patches or plaques, and calcinosis cutis, although with some side effects.
Other treatments like colchicine, which has anti-inflammatory properties, along with intravenous immunoglobulin (IVIG) and intralesional corticosteroid injections have been used effectively against this condition. Surgery is the most common treatment method, but carbon dioxide laser light treatment may also be beneficial for treating small lesions and those on the fingers.
What else can Calcinosis Cutis be?
When it comes to skin disorders, a few examples that doctors consider include:
- Cutaneous mycetoma (a fungal skin infection)
- Genital warts
- Milia (small white bumps usually on the face)
- Molluscum contagiosum (a viral infection that causes skin bumps)
- Osteoma cutis (bone-like bumps on the skin)
- Xanthomas (fatty deposits under the skin)
