Myelodysplastic syndromes (MDS) are disorders where the bone marrow produces immature or defective blood cells. This failure to produce healthy cells leads to persistent low counts of one or more blood cell types. While MDS is a disease of the blood and marrow, its effects can appear on the skin. These cutaneous manifestations can be diverse and may arise before other signs of the disease are recognized, serving as an external clue to an internal issue.
The Connection Between MDS and Skin Conditions
The link between this bone marrow disorder and skin abnormalities occurs through several pathways. One of the most direct connections involves the infiltration of abnormal cells into the skin. In some cases of MDS, immature blast cells can escape the bone marrow, travel through the bloodstream, and accumulate in the dermal layers. This process is a direct extension of the disease to a secondary site.
A more indirect cause is the body’s immune response, known as a paraneoplastic syndrome. The immune system’s reaction to the presence of abnormal cells can trigger systemic inflammation and a variety of dermatologic conditions. The skin becomes a site of reaction, displaying inflammatory symptoms not caused by direct infiltration. Finally, the low blood cell counts (cytopenias) that define MDS are a major contributor to skin problems, which are detailed later.
Specific Dermatologic Manifestations
Leukemia cutis represents a direct infiltration of leukemic or pre-leukemic cells into the skin. It appears as firm, raised papules, nodules, or larger, flat-topped plaques. The color of these lesions can range from red to purplish or may match the patient’s skin tone. The presence of leukemia cutis often indicates a more aggressive form of MDS or its transformation into acute myeloid leukemia (AML).
Neutrophilic dermatoses are inflammatory conditions characterized by a dense accumulation of neutrophils in the skin. Sweet’s syndrome is a well-known example, presenting with the abrupt onset of tender, red or bluish-red plaques and nodules, often accompanied by fever. These lesions are a reactive phenomenon, reflecting the body’s response to the marrow disorder.
Pyoderma gangrenosum is another neutrophilic dermatosis linked to MDS. It begins as a painful pustule or nodule that rapidly progresses into an expanding ulcer. These ulcers are notable for their undermined, irregular borders with a distinct purplish or dusky hue. The condition is an inflammatory disorder, not an infection, and may lead to significant scarring.
Vasculitis, or inflammation of the blood vessels in the skin, is also seen in patients with MDS. When blood vessels become inflamed, they can become weak and leaky, leading to signs like palpable purpura (raised spots), rashes, hives, or painful nodules. In more severe cases, restricted blood flow can cause tissue death and skin ulcers.
Non-Specific Skin Changes and Complications
Many skin changes in MDS are direct consequences of the disease’s impact on blood cell counts. Low platelet levels (thrombocytopenia) reduce the body’s ability to form clots, leading to spontaneous bleeding beneath the skin. This can manifest as petechiae, which are tiny, pinpoint-sized red or purple dots, or as purpura, which are larger bruises that appear without any known injury.
The chronic shortage of red blood cells (anemia) also produces visible signs. Hemoglobin in red blood cells gives skin its rosy undertones, so when counts are low, the skin can lose this color, resulting in pallor. This paleness is often most noticeable in the face, lips, and the creases of the palms.
A low count of neutrophils (neutropenia) compromises the immune system, leaving the body vulnerable to pathogens. The skin, as the body’s outer barrier, frequently becomes a site for bacterial infections like cellulitis or abscesses. Fungal infections can also take hold more easily.
Diagnosis and Management of Skin Lesions
When a person with MDS develops a new skin lesion, a skin biopsy is the standard procedure for diagnosis. A small sample of the affected skin is removed and examined by a pathologist to determine the cause. This analysis can distinguish between the direct infiltration of MDS cells, an inflammatory reaction like Sweet’s syndrome, vasculitis, or a secondary infection.
The management of skin manifestations addresses both the underlying disease and the lesions themselves. Treating the MDS is a priority, as improving bone marrow function and blood counts can lead to the resolution of associated skin problems. Therapies for MDS vary widely and may include growth factors, chemotherapy, or stem cell transplantation.
Specific treatments are also directed at the skin to provide relief. Inflammatory conditions like Sweet’s syndrome or vasculitis are often treated with corticosteroids, which can be applied topically or taken systemically. For painful ulcers like those in pyoderma gangrenosum, meticulous wound care is necessary to promote healing. If a skin biopsy confirms an infection, targeted antibiotics or antifungal medications are prescribed.