Dermatographic urticaria


dermatographia: Familial dermographism is a condition also known as skin writing. When people who have dermatographia lightly scratch their skin, the scratches redden into a raised wheal similar to hives. Signs and symptoms of dermatographia include raised red lines, swelling, inflammation, hive-like welts and itching. Symptoms usually disappear within 30 minutes. The exact cause of this condition is unknown. Treatment mayinvovle use of antihistamines if symptoms do not go away on their own.

Endpoint definition

FinnGen phenotype data

392423 individuals

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Apply sex-specific rule None


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Check conditions None


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Check pre-conditions, main-only, mode, registry filters

Hospital Discharge: ICD-10 L50.3
Hospital discharge: ICD-9 7083
Cause of death: ICD-10 L50.3
Cause of death: ICD-9 7083

2 out of 7 registries used, show all original rules.


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Check minimum number of events None


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Include endpoints None


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Remove individuals based on genotype QC


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Control definitions


Extra metadata

Level in the ICD hierarchy 4
First used in FinnGen datafreeze DF2
Parent code in ICD-10 L50
Name in latin Urticaria derm[at]ographica

Summary Statistics

Key figures

All Female Male
Number of individuals 1848 1467 381
Unadjusted prevalence (%) 0.49 0.70 0.23
Mean age at first event (years) 45.67 44.49 50.20


Follow-up Absolute risk HR [95% CI] p N
1998–2019 0.02 1.55 [0.79, 3.02] 2.0e-1 45
15 years 0.01 1.06 [0.54, 2.08] 8.6e-1 18
5 years 0.00 3.99 [2.16, 7.37] 1.0e-5 17
1 year - - - -

Age distribution of first events

Year distribution of first events

Cumulative Incidence


Index endpoint: L12_URTICA_DERTMATOG – Dermatographic urticaria
GWS hits:

Survival analyses between endpoints


before Dermatographic urticaria
after Dermatographic urticaria

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Drugs most likely to be purchased after Dermatographic urticaria

Endpoint not on priority list, no data to show.