Acne Vulgaris
Historical and physical clues that may suggest hormone-sensitive acne include onset between ages 20 and 30; worsening the week before a woman's period; acne lesions predominantly[en.wikipedia.org]
Atopic Dermatitis
Less than 2% will have an onset after age 20 years. Most sources agree that persistence after age 20 years is uncommon.[emedicine.medscape.com]
Diabetes Mellitus
[…] at age 20 years, normal weight (unlike most NIDDM) Characterized by PPP (polyuria, polydipsia, polyphagia) and ketoacidosis (DKA) Polyphagia combined with weight loss is[pathologyoutlines.com]
[…] antibodies Some NIDDM patients have autoantibodies but no other features of IDDM Usually chronic (years) Clinical disease when 90% of islet cells are destroyed Clinical features Onset[pathologyoutlines.com]
Infectious Mononucleosis
The risk of SLE with onset before age 20 years was 13-fold increased in individuals with a negative PB test.[dx.doi.org]
[…] before age 20 years in patients suspected of, but not found to have, IM.[dx.doi.org]
IM and perform diagnostic tests for IM in patients who present with unspecific initial symptoms of SLE, thus producing the observed pattern of increased risk of SLE with onset[dx.doi.org]
Keratitis
KSS is a slowly progressive mitochondrial disorder with onset before age 20 years.[ajnr.org]
Diabetic Nephropathy
[…] before age 20 Past or current cigarette use A family history of diabetic nephropathy The pathophysiology of the glomerulus in DN can best be understood by considering the[en.wikipedia.org]
[…] in people with diabetes that have one or more of the following conditions: Poor control of blood glucose Uncontrolled high blood pressure Type 1 diabetes mellitus, with onset[en.wikipedia.org]
Young-Onset Parkinson Disease
This organization also suggests this mutation affects 32 percent of people who experience onset between age 20 and 30.[healthline.com]
According to the National Parkinson Foundation, studies show that 65 percent of people with Parkinson’s who experience onset before age 20 may do so because of a genetic mutation[healthline.com]
Hereditary Late-Onset Parkinson Disease
Most cases of PD are sporadic (with no family history ), and with onset around 60 years of age; onset before age 20 years is considered to be juvenile-onset Parkinson disease[rarediseases.info.nih.gov]
Broadly speaking there are three basic divisions of Parkinson’s disease across different age ranges: Juvenile-onset Parkinson disease – onset before age 20 years Early-onset[scienceofparkinsons.com]
Diabetes Mellitus Type 1
[…] at age 20 years, normal weight (unlike most NIDDM) Characterized by PPP (polyuria, polydipsia, polyphagia) and ketoacidosis (DKA) Polyphagia combined with weight loss is[pathologyoutlines.com]
[…] antibodies Some NIDDM patients have autoantibodies but no other features of IDDM Usually chronic (years) Clinical disease when 90% of islet cells are destroyed Clinical features Onset[pathologyoutlines.com]
Progressive Myoclonic Epilepsy Type 3
. Patients with onset before age 20 years often present with the phenotype of PME, characterised by ataxia, seizures, myoclonus, and progressive intellectual deterioration[slideshare.net]