What Triggers Morphea?
Morphea is a skin disorder that is characterized by localized inflammation and fibrosis of the skin due to increased production of collagen by fibroblasts. It is a less severe form of scleroderma and is also known as localized scleroderma. Systemic scleroderma is the more severe form of scleroderma. Systemic sclerosis is causes thickening of the skin of fingers and toes known as sclerodactyly, nail fold capillaries, Raynaud’s phenomenon, telangiectasia, fibrosis and vascular changes of internal organs.
What Triggers Morphea?
For the most part, the cause of morphea still remains unknown. Although, no definitive etiology has been identified, it is established that it is not contagious, infectious or malignant and is neither hereditary. There have been various hypothesis surrounding morphea etiologies and triggers, which include autoimmunity, vascular irregularities, infections, cancer or lymphoma, radiation, genetics, medication, vaccinations and chemicals.
Autoimmunity is the abnormal response of the body when autoantibodies start attacking body’s own healthy cells and tissues. Autoimmunity is the most common hypothesis related to morphea and has been linked to other autoimmune diseases and considered a part of MAS (multiple autoimmune syndromes). Other autoimmune conditions linked to it are vasculitis, vitiligo, Hashimoto’s thyroiditis, autoimmune thrombocytopenic purpura. Approximately 40% of patients with severe forms of morphea have been associated with personal or family history of autoimmune diseases.
Several studies have linked Borrelia burgdorferi (Lyme’s disease) to morphea and Toxoplasma gondii infection is also associated with localized morphea. Several case studies also report of a link between T-cell lymphoma caused due to HTLV-1 virus infection. This virus has been associated with guttate form of morphea.
Radiation has been a common trigger for morphea and several case studies have linked these two. Irradiation post cancer is the most common trigger. Morphea could occur either in the proximity of the irradiation or distant to irradiation.
Although, it is not passed from parents to offspring, it has been linked to certain genes that may trigger the disease; hence, it is supposed to have genetic predisposition. Localized genetic factors have been identified, such as cutaneous mosaicism has been known to affect linear morphea.
Medications have also been linked to increase the chances of morphea and these include valproic acid L tryptophan.
Vaccinations, such as pneumococcal vaccination and injections, such as bleomycin and silicone have been found to cause morphea. Primary atrophic solitary morphea profunda and lipoatrophy like lesions have been found related to vaccinations and injections at the site of injection.
Organic solvents and chemicals have been known to trigger morphea. Patients exposed to occupational organic solvents and silica dust and PVC were at a higher risk of developing morphea.
Repeated trauma, friction and penetrating wound have also been linked to vascular and connective tissue changes leading to morphea.
Although, it is still not clear how these triggers bring about changes in vascular system and connective tissue metabolism and lead to morphea. There is still ongoing research and researchers hypothesize that there are a number of factors leading to such changes.
Morphea is three times more common in females than in males and affects approximately 3 out of a million people. The patches of morphea can be seen mostly in the abdomen, chest, back, extremities and on rare occasions on the face and scalp.
Morphea is classified depending on the localization and involvement of the underlying tissue, and include localized or circumscribed morphea, generalized morphea, linear morphea, and pansclerotic morphea. Localized morphea involves the outer dermal layer limited to one or several patches. Generalized morphea involves a larger area of skin. Linear morphea is a linear streak that may affect the outer skin along with deeper layers, including muscles and bone. Pansclerotic morphea is more severe form of morphea that affects the outer layer along with the connective tissue, muscles and bone. This form of morphea has a tendency to cause deformity and disability of the affected part, such as if a limb is involved then it may lead to limitation of movement of that limb.