With the return to classes we can find ourselves before a case of lice . How does the contagion take place? Can they be prevented? What can we do once we have them? Two members of the Spanish Academy of Dermatology and Venereology (AEDV) answer these questions.
” Lice have no preference for hair, sex or age , but it is believed that long hair is the main cause that explains the higher incidence in girls, ” explains Gloria Garnacho, member of the AEDV. If you have long hair, it is recommended to pick it up , since it favors contact with other hair. In addition, in this type of manes, the treatments present more difficulties to execute and their effectiveness may be less. ” They are more frequent in children due to the way they relate, with closer physical contact, but nevertheless, they can also be spread by adults, ” added the expert.
How does the contagion take place?
“The contagion occurs by direct head-to-head contact and, exceptionally, by passive transport through infected objects . Lice attach to the hair of the new host and begin to deposit nits (eggs), thus starting a new generation of these insects ”, explains Esther Jiménez Blázquez, member of the AEDV. According to the specialist, itching is the first symptom that is suffered, but its appearance may not be imminent , delaying its diagnosis and helping its spread.
The pediculosis “is one of the most prevalent infectious diseases, especially in children, and although there may be throughout the year , there are two peaks, one in summer and another in autumn , ” says Garnacho.
Beware of ineffective folk remedies
For Garnacho, the best measure to prevent lice is the periodic examination of the head . For his part, Jiménez explains the popular remedies that have been used and whose efficacy is doubtful for their prevention: “ Essential oils, such as tea tree, coconut oil, petroleum jelly or mayonnaise, act by choking the louse but they seem to be less effective than classic chemical pediculicides . ” Furthermore, “some essential oils can be irritating when used in high concentrations and often require frequent applications (every three days), making them difficult to remove, ” he adds.
Another remedy that has traditionally been used to prevent lice has been vinegar , whose “direct action against the insect requires high concentrations with limited efficacy and potential for irritation . However, with dilutions of two parts, one of water and the other of vinegar , it does help to facilitate the detachment of the nits and can be useful for this purpose ”, Jiménez explains.
How to fight them?
Once the louse is in our hair, the spread occurs: “The hatching of the nits occurs after seven days , giving rise to a nymph that resembles the adult louse, a state that is reached after about 10 days” , explains Garnacho. If an appropriate ovicidal and pediculicidal agent is applied , two treatments must be carried out so that it acts on the insect’s nervous system:
- With the first treatment, on “day zero all lice and eggs will die, except those that were laid just before the treatment and those newly hatched after its removal.”
- With the second treatment, on day seven the remaining eggs fromthe first procedure are finished .
If the agent is only pediculicide, three treatments must be carried out every seven days:
- ” On day zeroall the lice will die, leaving only the newly laid eggs and the eggs about to hatch .”
- In the second treatment, to be carried out on day seven, hatched eggs will be eliminated , so “these nymphs will not have time to mature until the adult louse”.
- The third treatmentwill take place between the 13th and 15th, and with it the adult lice will be killed .
