Topical steroid

Topical steroids are the topical forms of corticosteroids. Topical steroids are the most commonly prescribed topical medications for the treatment of rash, eczema, and dermatitis. Topical steroids have anti-inflammatory properties, and are classified based on their skin vasoconstrictive abilities. There are numerous topical steroid products. All the preparations in each class have the same anti-inflammatory properties, but essentially differ in base and price.
Side effects may occur from long-term topical steroid use.
Medical uses.
Weaker topical steroids are utilized for thin-skinned and sensitive areas, especially areas under occlusion, such as the armpit, groin, buttock crease, and breast folds. Weaker steroids are used on the face, eyelids, diaper area, perianal skin, and intertrigo of the groin or body folds. Moderate steroids are used for atopic dermatitis, nummular eczema, xerotic eczema, lichen sclerosis et atrophicus of the vulva, scabies (after scabiecide) and severe dermatitis. Strong steroids are used for psoriasis, lichen planus, discoid lupus, chapped feet, lichen simplex chronicus, severe poison ivy exposure, alopecia areata, nummular eczema, and severe atopic dermatitis in adults.
To prevent tachyphylaxis, a topical steroid is often prescribed to be used on a week on, week off routine. Some recommend using the topical steroid for 3 consecutive days on, followed by 4 consecutive days off. Long-term use of topical steroids can lead to secondary infection with fungus or bacteria (see tinea incognito), skin atrophy, telangiectasia (prominent blood vessels), skin bruising and fragility.
The use of the finger tip unit may be helpful in guiding how much topical steroid is required to cover different areas of the body.
Safety in pregnancy.
A 2015 meta-analysis of observational studies of pregnancies found no association between mothers' use of topical steroids and type of delivery, APGAR score, birth defects, or prematurity.
Classification systems.
USA system.
The USA system utilizes 7 classes, which are classified by their ability to constrict capillaries and cause skin blanching. Class I is the strongest, or superpotent. Class VII is the weakest and mildest.
Class I.
Very potent: up to 600 times stronger than hydrocortisone
Class VII.
The weakest class of topical steroids. Has poor lipid permeability, and can not penetrate mucous membranes well.
Other countries.
Most other countries, such as the United Kingdom, Germany, the Netherlands, New Zealand, recognize only 4 classes. In the United Kingdom and New Zealand I is the strongest, while in Continental Europe, class IV is regarded as the strongest.
Class IV (UK/NZ: class I).
Very potent (up to 600 times as potent as hydrocortisone)
Class III (UK/NZ: class II).
Potent (50–100 times as potent as hydrocortisone)
Class II (UK/NZ: class III).
Moderate (2–25 times as potent as hydrocortisone) 
Class I (UK/NZ: class IV).
Mild
Japan classification.
Japan rates topical steroids from 1 to 5, with 1 being strongest.
Allergy associations.
The highlighted steroids are often used in the screening of allergies to topical steroid and systemic steroids. When one is allergic to one group, one is allergic to all steroids in that group.
Group A.
Hydrocortisone, hydrocortisone acetate, cortisone acetate, tixocortol pivalate, prednisolone, methylprednisolone, and prednisone
Group B.
Triamcinolone acetonide, triamcinolone alcohol, amcinonide, budesonide, desonide, fluocinonide, fluocinolone acetonide, and halcinonide
Group C.
Betamethasone, betamethasone sodium phosphate, dexamethasone, dexamethasone sodium phosphate, and fluocortolone
Group D.
Hydrocortisone 17-butyrate, hydrocortisone-17-valerate, alclometasone dipropionate, betamethasone valerate, betamethasone dipropionate, prednicarbate, clobetasone-17-butyrate, Clobetasol-17 propionate, fluocortolone caproate, fluocortolone pivalate, fluprednidene acetate, and mometasone furoate
History.
Corticosteroids were first made available for general use around 1950.