1. Fibrodysplasia ossificans progressiva
Fibrodysplasia ossificans progressiva is a rare disorder which causes the disabling condition, and it is characterized by the formation of bony bars within the muscles of the body. Usually, the bone formation is noticed in early childhood, and it appears as a hard lump in the neck or along the spine. These bumps are generally tender, and they gradually shrink in size as a bone replaces an affected muscle. Fibrodysplasia ossificans progressiva is particularly disabling in children, and it is defined by two cardinal features, namely, heterotopic progressive osteogenesis and congenital abnormalities of the great toes.
Heterotopic progressive osteogenesis is a condition in which the lamellar bone is present at the locations where the bone does not generally exist.
Congenital abnormalities of the great toes. Congenital abnormalities are the structural abnormalities that are caused due to faulty development, present at birth, and these abnormalities are the major causes of prenatal mortality and morbidity.
Most often, the diagnosis of this disease is left unnoticed, and this is because it is often misdiagnosed. Diagnosis of this disease is crucial because the delayed or incorrect diagnosis can cause much pain and suffering for both sufferers as well as for the family.
2. Encephalitis lethargica
Encephalitis lethargica is a neurological syndrome which attacks the brain and causes a wide variety of symptoms. Encephalitis lethargica is characterized by acute and chronic phase.
During the acute phase, patients experience symptoms that include excessive sleepiness, fever, disorders of ocular motility, and movement disorders. Most often, the onset of the non-descript symptoms that are associated with acute encephalitis lethargica is gradual, and it includes malaise, pharyngitis, shivering, headache, vertigo, and vomiting.
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Typically, the chronic phase of encephalitis lethargica develops one to five years after the acute period, but it can also occur immediately after the acute phase or five years after the acute phase. Some of the standard features of chronic encephalitis lethargica include Parkinson's disease, sleep disturbances, oculomotor abnormalities, respiratory disorders, psychiatric disorders, and involuntary movements. Chronic encephalitis lethargica can also be associated with other movement disorders such as chorea, spasm, and tics that affect the jaw, lip, and tongue.
The exact cause of encephalitis lethargica is not known yet. Multiple studies suggest that this disease can be considered as a heterogeneous group of diseases rather than a unitary entity, that occurs with unexplained neurological symptoms. Although encephalitis lethargica affect people of all ages, people between the age of 10 to 15 are more likely to develop this disorder.
The porphyrias are metabolic disorders that arise from defects in the heme biosynthetic pathway. Each porphyria is associated with specific partial enzyme deficiency, which leads to the altered patterns of synthesis of porphyrins and their prosecutors and is linked to the development of various clinical manifestations. Porphyria is a group of seven inherited metabolic disorders that are caused by seven different faulty genes. There are two possible effects of porphyrias, acute attacks, and skin sensitivity.
Acute attacks cause severe illness, and it is caused by the build-up of aminolevulinic acid and porphobilinogen, the raw materials that are used for making heem. Acute attacks can cause symptoms like severe pain, nausea, constipation, vomiting, change in color of urine, high blood pressure, and change in movements of arms and legs.
Skin sensitivity in sunlight causes significant harm to the skin, and it is worse than sunburn. The buildup of light-sensitive porphyrins causes skin problems. The symptoms depend on the type of porphyria, some types can cause redness, and some examples can lead to the occurrence of blisters.
4. Cotard’s delusion
Cotard’s delusion is a rare and severe mental disorder in which an affected individual holds a delusional belief that he or she is dead and does not exist or has lost his or her internal organs or blood. Cotard’s delusion syndrome is associated with various degrees of severity, ranging from mild to severe. Generally, in the mild state, a patient having cotard’s delusion syndrome experience the feeling of despair and self-loathing. Whereas, in the severe state, a patient having cotard’s delusion syndrome start feeling that they do not exist and they deny to believe in their existence.
5. Adiposis dolorosa
Adipose Dolorosa, also known as dercum disease, is a rare skin condition which occurs due to the growth of harmful and painful fatty tumors. These tumors are made up of fat tissues is known as the lipoma, and these lipomas appear all over the body and are usually found in multiple extremities. Although the exact cause of this disease is not known yet, multiple researchers have suggested some possible causes and some of the possible causes include nervous system dysfunction, mechanical pressure on nerves, adipose tissue dysfunction and trauma.
Adiposis dolorosa is associated with a wide range of symptoms such as excessive weight gain, emotional instability, weakness, trouble with sleeping, memory issues, confusion, joint aches, and shortness of breath. Most often, the people who suffer from this disease did not have any family history of adiposis dolorosa, but few cases of inheritance from family have also been reported.
Tags: rare diseases list and symptoms, top 20 rare diseases, list of rare diseases by prevalence, rare fatal childhood diseases
Annie is the oldest writer at Cheap Medicine Shop and is the subject and publishing expert. She has a graduate degree in medicines along with a diploma in creative writing.