It is possible that the black vertical line on the boy's thumb nail is a result of a melanonychia striata, which is a linear nail melanin pigmentation. It is relatively common in children and is generally harmless. However, it is important to have it evaluated by a doctor, especially if it is growing, to rule out any underlying medical conditions.

If this did happen, don’t panic too much, as it can occur. Ketoconazole contains an ingredient that can be harmful when ingested. Symptoms such as stomach ache, nausea, or vomiting are likely to occur. If you notice any of these signs, seek medical attention immediately. In the meantime, try not to get too worked up about it. Instead, drink plenty of water to help reduce the concentration of the drug in your system.

Your description of the symptoms leads me to believe that your mother has a skin condition called eczema. Eczema is characterized by the appearance of red, itchy patches on the skin. It can be caused or aggravated by certain substances or environmental factors. To alleviate the symptoms, it is necessary to maintain the skin's hydration and avoid irritants. Using mild soaps and wearing comfortable, breathable clothes can also be helpful.

It seems to be a fungal infection in your left armpit. I suggest you see a dermatologist to look into the rash, and get a medication accordingly. Deodorant should also be avoided as it might make the situation worse.
 

Allergic reactions on face:1.Give a cold compression by using ice cold gel packs. 2. You can use alovera gel application . 3. If severe then topical corticosteroid have to be used along with oral antihistamines like cetrizine.

Hair loss can be due to several factors such as stress, unhealthy diet, or hormone variations. It's normal for humans to shed up to 100 strands of hair daily. But if it's a lot more than usual, you might notice bald spots or thinner hair. Eating well, calming your mind, and using hair products that are not too harsh may help to prevent hair loss. 

Stretch marks on the­ bum are pretty normal. They happe­n when skin expands rapidly, like during pube­rty, pregnancy, or weight gain. Basically, the marks form whe­n deeper laye­rs tear. To reduce the­ir appearance, moisturize re­gularly with retinol or hyaluronic acid products. Proper nutrition and hydration can lend a hand too. Ke­ep in mind, fading takes time, so stick with the­ routine patiently. The marks look purple­ at first, but gradually lighten over months.

You've been dealing with ringworm for a long time. Ringworm is a common fungus infection that can appear in different parts of your skin and cause red, itchy, circular rashes. Furthermore, while the drug takes away the discomfort, returning too soon may lead to a relapse. Regularly washing your clothes and bedding will also help limit the infection.