Contact dermatitishttps://en.wikipedia.org/wiki/Contact_dermatitis
Contact dermatitis is a type of common inflammation that induces pruritus. Symptoms of contact dermatitis include itchy or dry skin, a red rash, bumps, and swelling. If symptoms are severe, they may appear in the form of itchy blisters.

Contact dermatitis results from either exposure to allergens (allergic contact dermatitis) or irritants (irritant contact dermatitis). Phototoxic dermatitis occurs by sunlight.

Signs and symptoms
Contact dermatitis is a localized rash or irritation of the skin caused by contact with a foreign substance. These can take anywhere from several days to weeks to heal. Contact dermatitis fades only if the skin no longer comes in contact with the allergen or irritant for a long time (after days).

There are three types of contact dermatitis: (1) irritant contact dermatitis (2) allergic contact dermatitis (3) photocontact dermatitis. Irritant dermatitis is usually confined to the area where the trigger actually touched the skin, whereas allergic dermatitis may be more widespread on the skin.

Common causes of allergic contact dermatitis include:
Nickel, 14K or 18K gold, Chromium, Poison ivy (Toxicodendron radicans)

Patch test
The top three allergens found in patch tests were:
Nickel sulfate (19.0%), Myroxylon pereirae (Balsam of Peru, 11.9%), Fragrance mix (11.5%)

Treatment
Do not use soap and cosmetics. In particular, the use of sunscreen or other cosmetics may result in the repeated dryness or itching on the face, which occurs mainly in women. Reduce sun exposure if the symptom exclusively occurs in sun-exposed body areas.

Treatment ― OTC Drugs
Taking antihistamine is helpful. Cetirizine or levocetirizine are more effective than fexofenadine but make you drowsy.
#Cetirizine [Zytec]
#Diphenhydramine [Benadryl]
#LevoCetirizine [Xyzal]
#Fexofenadine [Allegra]
#Loratadine [Claritin]

OTC steroid ointment may be used to the affected area for several days.
#Hydrocortisone ointment
  • Contact dermatitis around a wound. It occurred around the area where the skin was injured for a long period. The cause is presumed to be an ointment or dressing materials applied to the wound.
  • In case of severe Contact dermatitis, small blisters along with severe itching can occur.
  • Severe Contact dermatitis ― buprenorphine transdermal patch. The cause may be either the drug itself or the adhesive component in the patch.
  • 5 days after contact with the causative agent (Urushiol).
  • Local exposure to strong allergens can also be a cause.
  • A 3-year-old girl with Contact dermatitis caused by poison ivy (plant) ― Poison ivy (plant) is a potent allergen and is a common cause of Contact dermatitis on the legs. In severe cases, blisters may also appear.
  • Sunburn occurred on the area where shoes were worn.
  • You should suspect not only contact dermatitis but also fungal infection. If it doesn't itch too much, you should consider using an antifungal ointment along with it.
    If it itches a lot, it is a strong case of eczema, so it is believed that symptoms will improve only if you take antihistamines for more than two weeks and apply a lot of steroid ointment.
  • 7 days after contact with the causative agent (Urushiol).
References Diagnosis and Management of Contact Dermatitis 20672788
Contact dermatitis is a common skin condition that causes red, itchy patches after contact with certain substances. There are two types: irritant and allergic. Irritant contact dermatitis happens when something irritates the skin directly, while allergic contact dermatitis is a delayed reaction to a substance touching the skin. Common triggers include poison ivy, nickel, and fragrances. Symptoms typically include redness, scaling, itching, and sometimes blisters. Acute cases can be severe, with redness, blistering, and swelling, while chronic cases may involve cracked, scaly skin. Diagnosis usually involves identifying and avoiding the irritant. Treatment often includes steroid creams for localized reactions and oral steroids for widespread ones. However, steroids should be tapered off gradually to prevent a rebound reaction.
 Contact dermatitis 9048524
The doctor treating a patient with a rash resembling eczema needs to know all the possible reasons for this condition. It's important to consider if something the patient is in contact with could be causing the rash, especially if it doesn't go away with usual treatment.
 Novel insights into contact dermatitis 35183605
Contact dermatitis is a frequent skin condition triggered by repeated exposure to substances that cause allergies or irritation, leading to either allergic contact dermatitis or irritant contact dermatitis.