Parathyroid Disease
Parathyroid disease, which includes both hyperparathyroidism and hypoparathyroidism, directly upsets the balance of parathyroid hormone (PTH), calcium and phosphate. PTH and circulating calcium are central to maintaining cell membrane potential, desmosomal adhesion between keratinocytes, epidermal differentiation, the hair follicle cycle and the tone of blood vessels in the dermis. When the parathyroid glands malfunction, skin changes can range from mild dryness and roughness to calciphylaxis, a calcifying, necrotizing small-vessel disease with high mortality.
How it affects skin cells and the microcirculation:
- Hyperparathyroidism:
- High PTH and the calcium–phosphate product: elevated PTH pulls calcium out of bone into the blood. When the Ca x P product exceeds 55, calcium phosphate precipitates as hydroxyapatite crystals in capillary basement membranes, elastic fibers and the smooth muscle cells of dermal blood vessels.
- Small-vessel blockage and necrosis (calciphylaxis / calcific uremic arteriolopathy): calcium crystals settle in the media of small arterioles in the skin, triggering intimal proliferation and local clots that suddenly cut off the blood supply. The resulting ischemia causes widespread skin necrosis and extremely painful black ulcers.
- Hyperparathyroid itch: high PTH prompts mast cells to release histamine, while calcium phosphate deposits around sensory nerve endings in the dermis add to the itch.
- Hypoparathyroidism:
- Low calcium and disordered epidermal differentiation (hypocalcemia): intracellular calcium is the signal that drives keratinocyte differentiation and desmosomal adhesion. Low blood calcium disrupts these connections and reduces lipid production in the stratum corneum, leaving the skin severely dehydrated (xerosis), thin, fragile and scaly.
- Triggering generalized pustular psoriasis: chronic hypocalcemia makes the skin more prone to inflammation and is a leading trigger for generalized pustular psoriasis and for pustular psoriasis of pregnancy (impetigo herpetiformis).
At Haute-Derma, managing skin problems caused by parathyroid disease means spotting vascular warning signs early, ruling out calcifying necrosis and gently restoring the skin barrier.
Skin, Hair and Nail Signs by Parathyroid Status
| Organ / Structure | Hyperparathyroidism | Hypoparathyroidism |
|---|---|---|
| Skin and Mucous Membranes | Persistent generalized itch (especially in chronic kidney disease). Hard white or yellow nodules under the skin (calcinosis cutis). | Rough, dry, cracked skin with fish-like scaling (ichthyosiform). Chronic mucocutaneous candidiasis (in APS-1 syndrome). |
| Vascular Complications | Calciphylaxis: a net-like violaceous pattern (livedo reticularis) that progresses to extremely painful black necrotic plaques. | No vascular necrosis, but a higher risk of acute generalized pustular psoriasis. |
| Hair | Hair is rarely affected directly (except for hair loss from scratching). | Dry, brittle, thinning hair; patchy hair loss (alopecia areata) or diffuse shedding. Sparse eyebrows. |
| Nails | Nails may be mildly deformed by bony changes (resorption and sclerosis) in the fingertip bones. | Brittle nails, transverse ridges (Beau's lines) and separation of the nail from the nail bed (onycholysis). |
Calcinosis Cutis vs. Calciphylaxis: Key Differences
| Feature | Calcinosis Cutis | Calciphylaxis (CUA) |
|---|---|---|
| Where Calcium Is Deposited | Dermal connective tissue and subcutaneous fat | Intima and media of small arterioles in the skin |
| Lesion Appearance | Stone-hard, painless white or yellow papules, nodules or plaques under the skin | Net-like violaceous patches that quickly turn into black, crusted necrotic ulcers |
| Pain | Painless, or only mildly tender with pressure or friction | Severe pain, out of proportion to what is visible |
| Typical Sites | Around joints, fingers, areas exposed to friction | Areas with more fat: thighs, abdomen, buttocks, lower legs |
| Severity | Benign; mainly a cosmetic concern | A medical emergency with high mortality (50–80%), mostly from septic shock |
Medical Management and Treatment at Haute-Derma
Our goal at Haute-Derma is to protect the skin's microcirculation as much as possible and to restore the lipid barrier safely:
Initial Medical Assessment and Screening
- Metabolic blood tests: intact PTH, total calcium, ionized calcium, phosphate, Ca x P product, vitamin D (25(OH)D) and estimated glomerular filtration rate (eGFR).
- Assessing small-vessel damage and hard deposits: dermoscopy is used to look for a violaceous ischemic halo around lesions, and high-frequency skin ultrasound (HFUS) shows how deep the calcium deposits lie.
Conservative, Evidence-Based Treatment
- Relieving Itch and Repairing the Barrier in Hyperparathyroidism:
- Phototherapy: narrowband UVB reduces the number of mast cells in the dermis and calms nerve sensitivity, effectively easing parathyroid-related itch.
- Soothing anti-itch moisturizers: creams with calamine and a little menthol, combined with ceramides and polidocanol, quickly calm the itch and prevent scratch wounds that can become infected.
- Treating Dry Skin and Brittle Nails in Hypoparathyroidism:
- Restoring the lipid barrier: a moisturizer with 10% urea and lactic acid helps normalize keratinocyte differentiation in calcium-deficient skin.
- Medical nail and hair care: a serum with biotin, panthenol and hydrolyzed keratin helps strengthen brittle nail plates.
- Managing Vascular Damage and Calcification: if calciphylaxis is suspected (painful violaceous patches), the patient is referred urgently to endocrinology and nephrology for treatment with sodium thiosulfate.
Strict Contraindications at Haute-Derma
- No laser (CO2, picosecond, IPL), chemical peels, microneedling or mesotherapy injections on skin with calcinosis cutis or violaceous calciphylaxis patches: the blood vessels here are already narrowed or blocked by calcium. Any heat or mechanical injury can cause irreversible necrosis and chronic ulcers.
- No squeezing, cutting or draining of calcium nodules at beauty salons: opening a nodule gives bacteria a way in and, with poor blood supply, can easily lead to cellulitis and bloodstream infection.
- No self-directed skin-whitening treatments, harsh exfoliation or strong chemical scrubs in patients with parathyroid- or dialysis-related itch: these break down an epidermal barrier that is already thin from low calcium or high PTH and raise the risk of secondary infection with Staphylococcus aureus.
